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QNT/275

STATISTICS FOR DECISION MAKING

 

The Latest Version A+ Study Guide

 

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QNT 275 Week 1 Practice: Connect Knowledge Check
Complete the Week 1 Knowledge Check in Connect.

Note: You have unlimited attempts available to complete practice assignments.

 

 1.

Daily temperature in a local community collected over a 30-day time period is an example of cross-sectional data.

 

True

False

 

2.

Time series data are data collected at the same time period. 



True

False

 

3.

Primary data are data collected by an individual.

 

True

False

 

4.

A random sample is selected so that every element in the population has the same chance of being included in the sample.

 

True

False

 

5.

__________ consists of a set of concepts and techniques that are used to describe populations and samples.

 

Data mining

Traditional statistics

Random sampling

Time series analysis

 

6.

A sequence of operations that takes inputs and turns them into outputs is a ____________.

 

statistical inference

process

random sampling

runs plot

 

7.

Processes produce outputs over time.

 

True

False

 

8.

_________ uses traditional or newer graphics to present visual summaries of business information.

 

Data mining

Descriptive analytics

Predictive analytics

Association learning

 

 

9.

The number of sick days taken by employees in 2008 for the top 10 technology companies is an example of time series data.

 

True

False

 

10.

A population is a set of existing units.

 

True

False

 

 11.

A(n) _____________ variable is a qualitative variable such that there is no meaningful ordering or ranking of the categories.

 

interval

ordinal

ratio

nominative

 

12.

Judgment sampling occurs when a person who is extremely knowledgeable about the population under consideration selects the population element(s) that they feel is(are) most representative of the population.

 

True

False

 

A population is a set of existing units.

True

False

 

 

Processes produce outputs over time.

True

False

 

Primary data are data collected by an individual.

True

False

 

It is possible to use a random sample from a population to make statistical inferences about the entire population.

True

False

 

The term big data was derived from the use of survey data.

True

False

 

_________ uses traditional or newer graphics to present visual summaries of business information.

Predictive analytics

Data mining

Descriptive analytics

Association learning

 

An example of a qualitative variable is the mileage of a car.

True

False

Any characteristic of an element is called a ____________.

process

set

variable

D)census

 

A sequence of operations that takes inputs and turns them into outputs is a ____________.

random sampling

statistical inference

     process

runs plot

 

 

Daily temperature in a local community collected over a 30-day time period is an example of cross-sectional data.

True

False

 

 

An example of a quantitative variable is the manufacturer of a car.

True

False

 

Cross-sectional data are data collected at the same point in time.

True

False

 

 

 

QNT 275 Week 1 Apply Connect Week 1 Exercise

Review the glossary in your textbook in preparation for this assignment.

Complete the Week 1 Exercise in Connect.

Note: You have only 1 attempt available to complete assignments.

1.

Define Ratio Variable.

 

A variable having values that are numbers which reflect quantities or measurements.

A characteristic from a sample or population that can assume different values for individual elements (members) of the sample or population.

A quantitative variable such that ratios of its values are meaningful and for which there is an inherently defined zero value.

Facts and figures from which conclusions may be drawn, generally for a specific study or issue.

 

2.

Define Inferential Statistics.

 

Efforts to mislead users of statistical information including biased sampling, misleading chart, table and descriptive measures, and inappropriate analysis or inappropriate interpretation of the results.

The process of using a sample of measurements/values to make generalizations about the important aspects of a population of measurements/values.

A sampling design in which we divide a population into subgroups that do not overlap, then select a random sample from each subgroup (stratum).

A sample selected in such a way that every element in the population has an equal chance of being selected.

 

3.

Define Variable.

 

A characteristic from a sample or population that can assume different values for individual elements (members) of the sample or population.

A variable having values that indicate into which of several categories the value for the respective sample or population element belongs.

Data collected over several time periods.

A variable having values that are numbers which reflect quantities or measurements.

 

4.

Define Stratified Sampling.

 

Efforts to mislead users of statistical information including biased sampling, misleading chart, table and descriptive measures, and inappropriate analysis or inappropriate interpretation of the results.

A sampling design in which we divide a population into subgroups that do not overlap, then select a random sample from each subgroup (stratum).

A qualitative variable value for which there is no ordering or ranking; data values are not numerical and fit into categories.

A qualitative variable value for which there is ordering or ranking.

 

5.

Define Sample.

 

The process of organizing and describing important elements of a set of values.

A sample selected in such a way that every element in the population has an equal chance of being selected.

The process of using a sample of measurements/values to make generalizations about the important aspects of a population of measurements/values.

A subset of the elements in a population.

 

6.

Define Ordinal Variable.

 

A quantitative variable such that ratios of its values are not meaningful and for which there is not an inherently defined zero value.

Facts and figures from which conclusions may be drawn, generally for a specific study or issue.

A quantitative variable such that ratios of its values are meaningful and for which there is an inherently defined zero value.

A qualitative variable value for which there is ordering or ranking.

 

7.

Define Descriptive Statistics.

 

The process of using a sample of measurements/values to make generalizations about the important aspects of a population of measurements/values.

A sampling design in which we divide a population into subgroups that do not overlap, then select a random sample from each subgroup (stratum).

The process of organizing and describing important elements of a set of values.

A sample selected in such a way that every element in the population has an equal chance of being selected.

 

8.

Define Random Sampling.

 

A sampling design in which we divide a population into subgroups that do not overlap, then select a random sample from each subgroup (stratum).

A sample selected in such a way that every element in the population has an equal chance of being selected.

A qualitative variable value for which there is no ordering or ranking; data values are not numerical and fit into categories.

Efforts to mislead users of statistical information including biased sampling, misleading chart, table and descriptive measures, and inappropriate analysis or inappropriate interpretation of the results.

 

9.

Define Qualitative Variable.

 

A variable having values that indicate into which of several categories the value for the respective sample or population element belongs.

Data collected over several time periods.

The set of all elements about which we want to draw conclusions.

A subset of the elements in a population.

 

10.

Define Interval Variable.

 

Facts and figures from which conclusions may be drawn, generally for a specific study or issue.

A quantitative variable such that ratios of its values are not meaningful and for which there is not an inherently defined zero value.

A quantitative variable such that ratios of its values are meaningful and for which there is an inherently defined zero value.

A characteristic from a sample or population that can assume different values for individual elements (members) of the sample or population.

 

 

QNT 275 Week 2 Practice: Analysis ToolPak Installation
Complete the steps indicated in the "Installing the Analysis ToolPak" video to prepare for this week's assignment.

Take a screenshot of the Data tab showing the installed toolpak.

Click on the Assignment Files tab to submit your screenshot.

 

 

 

QNT 275 Week 2 Practice: Connect Knowledge Check
Complete the Week 2 Knowledge Check in Connect.

Note: You have unlimited attempts available to complete practice assignments.

1.

In a statistics class, 10 scores were randomly selected with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66.
What is the IQR?

 

11.00

10

5.00

5.25

12.00

 

 

2.

A quantity that measures the variation of a population or a sample relative to its mean is called the ____________.

 

range

interquartile range

standard deviation

coefficient of variation

variance

 

 

 

3.

An observation separated from the rest of the data is a(n) ___________.

 

absolute extreme

outlier

quartile

mode

 

 

4.

Quality control is an important issue at ACME Company, which manufactures light bulbs. To test the life-hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted: 378, 361, 350, 375, 200, 391, 375, 368, 321.
What is the mean?

 

375

389.9

368

346.6

200

 

 

 5.

In a statistics class, 10 scores were randomly selected with the following results (mean = 71.5): 74, 73, 77, 77, 71, 68, 65, 77, 67, 66.
What is the range?

 

516.20

144.00

22.72

4.77

12.00

 

 

 6.

Which percentile describes the first quartile, Q1?

 

25th

100th

75th

50th

 

 

7.

Personnel managers usually want to know where a job applicant ranked in his or her graduating class. With a grade point average of 3.83, Michelle Robinson graduated above the 93rd percentile of her graduating class. What is the percentile rank of a student whose GPA was the median GPA.

 

75th

50th

25th

93rd

10th

 

 

8.

All of the following are measures of central tendency except the ____________.

 

mode

range

mean

median

 

 

9.

Quality control is an important issue at ACME Company, which manufactures light bulbs. To test the life-hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted (mean = 346.6). 
378, 361, 350, 375, 200, 391, 375, 368, 321
What is the range?

 

58.5

191

3424.3

10,609

342.43

 

 

10.

The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes): 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118. 
What is the mean?

 

115.5

148

118

114.15

45

 

 

11.

The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes): 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118. 
What is the median?

 

118

115.5

45

114.15

148

 

 

12.

When establishing the classes for a frequency table, it is generally agreed that the more classes you use the better your frequency table will be.

 

True

False

 

 

 

QNT 275 Week 2 Apply: Connect Week 2 Case
Part 1

You manage the inventory for a car dealership. Your management would like you to review current inventory on the dealership lot.

Review the Week 2 Data Set.

Create and calculate the following in Excel®:

Create a Pie Chart which summarizes colors of the cars in the sample.
Create a Bar Chart which summarizes the frequency of the models of the cars in the sample.
Create a Frequency Table for classes of MPG, including Frequency and Relative Frequency for the cars in the sample.
Calculate the mean Days in Inventory for the cars in the sample. 
Compare that to the median and the mode.  
Highlight the value that would be a better representation of the "typical" price of a car in inventory?
Calculate the standard deviation of the Days in Inventory for the cars in the sample. 
Calculate the 5 number summary for the suggested retail prices of the cars in the sample. This consists of the 1st, 2nd, 3rd, 4th quartile and the IQR.
Note: Part 1 is not submitted. It is only to be completed in preparation for Part 2.

Part 2

Reference your Excel® spreadsheet from Part 1.

Complete the Week 2 Case in Connect.

Note: You have only 1 attempt available to complete assignments.

 

 

 

QNT 275 Week 3 Practice: Connect Knowledge Check
 1.

A plant manager knows that the number of boxes of supplies received weekly is normally distributed with a mean of 200 and a standard deviation of 20. What percentage of the time will fewer than 160 boxes of supplies arrive in a week?

2.28%

4.56%

42.07%

57.93%

 

 

2.

The z value tells us the number of standard deviations that a value x is from the mean.
 

True

False

 

 

3.

An event is a collection of sample space outcomes.

True

False

 

4.

Determine whether these two events are mutually exclusive: consumer with an unlisted phone number and a consumer who does not drive.

not mutually exclusive

mutually exclusive

 

 

 

 

 

5.

Determine whether these two events are mutually exclusive: unmarried person and a person with an employed spouse.

not mutually exclusive

mutually exclusive

 

6.

Which of the following statements about the binomial distribution is not correct?

Each trial results in a success or failure.

Trials are independent of each other.

The experiment consists of n identical trials.

The random variable of interest is continuous.

The probability of success remains constant from trial to trial.

 

7.

For a continuous random variable x, the height of the probability curve f(x) at a particular point indicates the value of the probability for that value.

True

False

 

 

 

8.

An important part of the customer service responsibilities of a cable company is the speed with which trouble in service can be repaired. Historically, the data show that the likelihood is 0.75 that troubles in a residential service can be repaired on the same day. For the first five troubles reported on a given day, what is the probability that all five will be repaired on the same day?

.2373

.9990

.0010

.6328

 

 

 

9.

A standard normal distribution has a mean of ____________ and standard deviation of ____________.

zero, one

zero, zero

one, zero

one, one

 

10.

A letter is drawn from the alphabet of 26 letters. What is the probability that the letter drawn is a vowel?

5/26

21/26

1/26

4/26

AEIOU; 5 vowels out of 26 letters.

 

11.

The set of all possible outcomes for an experiment is called a(n) ____________.

event

probability

sample space

experiment

 

 

12.

Using the following probability distribution table of the random variable x, what is the probability of x = 3?
 

 

5/15

2/15

1/15

3/15

 

 

 

QNT 275 Week 4 Apply: Connect Week 4 Case

Part 1
Three hundred consumers between 21 and 49 years old were randomly selected. After sampling a new wine cooler, each was asked to rate the appeal of the phrase: "Not sweet like wine coolers, not filling like beer, and more refreshing than wine or mixed drinks" as it relates to the new wine cooler. The rating was made on a scale from 1 to 5, with 5 representing "extremely appealing" and with 1 representing "not at all appealing".

As a manager overseeing the development of the concept, you bottle the wine cooler and placed it into distribution in one test store.

Your manager has asked you to assess the data and determine the most likely customer based on the ratings. Additionally, your manager would like you to review sales in the test store.

Use the Week 3 Data Set to create and calculate the following in Excel®:

Estimate the probability that a randomly selected 21 to 49 year old consumer:
Would give the phrase a rating of 5
Would give the phrase a rating of 3 or higher
Is in the 21-24 age group
Is a male who gives the phrase a rating of 4
Is a 35 to 49 year old who gives the phrase a rating of 1
Based on the probabilities for the ratings of 4 and 5, which age/gender demographic would be the best target audience for the new concept? 
Create a probability distribution using the data which shows how many cartons of the wine cooler were bought per customer in a month. 
Calculate the mean and the standard deviation of your probability distribution. 
Calculate the probability that exactly 3 six packs will be bought in a month.
Calculate the probability that between 4 and 8 six packs will be bought in a month.
Calculate the probability that at least 5 six packs will be bought in a month.
Calculate the probability that no more than 5 six packs will be bought in a month. 
Create a relative frequency distribution based on the wine cooler drinking temperatures. 
Create 6 bins with the same interval in each. 
Create a histogram
Considering the mean and standard deviation for the ideal drinking temperature: 
Calculate z values then refer to Table 6.1 - Cumulative Areas Under the Standard Normal Curve 
Calculate the probability of the wine cooler being less than 45 degrees.
Calculate the probability of the wine cooler being greater than 60 degrees.
Calculate the percentage of wine coolers served at the ideal temperature, between 49 and 55 degrees.
Part 2

Reference your Excel® spreadsheet from Part 1.

Complete the Week 3 Case in Connect.

Note: You have only 1 attempt available to complete assignments.

 

Part 1

You manage Human Relations for your company. One of your sales managers has retired, leaving an opening. You are considering two different employees for the position. Both are highly qualified so you have decided to evaluate their sales performance for the past year.

Use the Week 4 Data Set to create and calculate the following in Excel®:

1.       Determine the range of values in which you would expect to find the average weekly sales for the entire sales force in your company 90% of the time.

§  Calculate the impact of increasing the confidence level to 95%?

§  Calculate the impact of increasing the sample size to 150, assuming the same mean and standard deviation, but allowing the confidence level to remain at 90%?

2.       Based on the calculated confidence interval for weekly sales on the sample of 50 reps at a 90% confidence level:

§  Calculate both Reps’ average weekly performance and highlight if it is greater than the population mean.

3.       You want to determine whether there is a statistically different average weekly sales between Sales Rep A and Sales Rep B.

§  Create Null and Alternative Hypothesis statements that would allow you to determine whether their sales performance is statistically different or not.

§  Use a significance level of .05 to conduct a t-test of independent samples to compare the average weekly sales of the two candidates.

§  Calculate the p-value?

4.       Considering that individual you did not promote:

§  Determine whether this person’s average weekly sales are greater than the average weekly sales for the 50 sales reps whose data you used to develop confidence intervals.

§  Create Null and Alternative Hypothesis statements that would allow you to determine whether the new Sales Manager’s weekly average sales are greater than the sample of Sales Reps.

§  Use a significance level of .05 to conduct a t-test of independent samples to compare the average weekly sales of both.

§  Calculate the p-value?

SAMPLE OF WEEKLY SALES
Sales Rep  #
AverageWeekly Sales($)
 
Week #
Weekly Sales($) – Rep A
Weekly Sales($) – Rep B
 
1
1228
 
1
4657
5839
2
7374
 
2
6133
2602
3
1055
 
3
3438
2830
4
1859
 
4
7394
4763
5
3938
 
5
4327
3740
6
1692
 
6
2552
1315
7
569
 
7
7063
1599
8
4059
 
8
7844
1629
9
3689
 
9
6898
2416
10
607
 
10
4003
2107
11
1370
 
11
6884
4237
12
3735
 
12
4007
6322
13
3305
 
13
7214
2710
14
7228
 
14
2358
5890
15
6279
 
15
7745
5119
16
1671
 
16
1337
5184
17
5708
 
17
1052
3439
18
2569
 
18
6056
4828
19
4163
 
19
1495
3667
20
1519
 
20
3530
2518
21
7734
 
21
4749
6073
22
784
 
22
3833
5566
23
6766
 
23
7869
4555
24
7261
 
24
4541
5867
25
5034
 
25
6882
6039
26
7115
 
26
3868
1032
27
6291
 
27
5934
4834
28
6287
 
28
4447
3687
29
2080
 
29
5504
2214
30
7621
 
30
5554
4659
31
1047
 
 
 
 
 
32
6517
 
 
 
 
 
33
5172
 
 
 
 
 
34
3876
 
 
 
 
 
35
5429
 
 
 
 
 
36
4538
 
 
 
 
 
37
3786
 
 
 
 
 
38
2510
 
 
 
 
 
39
4863
 
 
 
 
 
40
7246
 
 
 
 
 
41
1175
 
 
 
 
 
42
641
 
 
 
 
 
43
4269
 
 
 
 
 
44
7034
 
 
 
 
 
45
3406
 
 
 
 
 
46
2256
 
 
 
 
 
47
3182
 
 
 
 
 
48
5178
 
 
 
 
 
49
4428
 
 
 
 
 
50
1189
 
 
 
 
 
 

 

QNT 275 Week 4 Practice Connect Knowledge Check

Based on a random sample of 25 units of product X, the average weight is 102 lb and the sample standard deviation is 10 lb. We would like to decide if there is enough evidence to establish that the average weight for the population of product X is greater than 100 lb. Therefore, the alternative hypothesis can be written as HA: μ  100. (Assume the population is normally distributed.)

True

False

 

 

The null hypothesis is a statement that will be accepted only if there is convincing sample evidence that it is true. 

True

False

 

 

A research study investigated differences between male and female students. Based on the study results, we can assume the population mean and standard deviation for the GPA of male students are µ = 3.5 and σ = 0.5. Suppose a random sample of 100 male students is selected and the GPA for each student is calculated. What is 

7.0

3.5

0.05

0.5

 

 

If we have a sample size of 100 and the estimate of the population proportion is .10, we can estimate the sampling distribution of     with a normal distribution.

True

False

 

The power of a statistical test is the probability of rejecting the null hypothesis when it is false.

True

False

 

A recent study conducted by the state government attempts to determine whether the voting public supports a further increase in cigarette taxes. The opinion poll recently sampled 1,500 voting age citizens. 1,020 of the sampled citizens were in favor of an increase in cigarette taxes. The state government would like to decide if there is enough evidence to establish whether the proportion of citizens supporting an increase in cigarette taxes is significantly greater than .66. What is the alternative hypothesis?

p ≤ .66

p < .66

p = .66

p  .66

 

The t distribution always has n degrees of freedom.

True

False

 

It has been reported that the average time to download the home page from a government website was 0.9 seconds. Suppose that the download times were normally distributed with a standard deviation of 0.3 seconds. If random samples of 23 download times are selected, describe the shape of the sampling distribution and how it was determined.

skewed; the original population is not a normal distribution

cannot be determined with the information that is given

normal; the original population is normal

normal; size of sample meets the Central Limit Theorem requirement

 

 

A recent study conducted by the state government attempts to determine whether the voting public supports a further increase in cigarette taxes. The opinion poll recently sampled 1,500 voting age citizens. 1,020 of the sampled citizens were in favor of an increase in cigarette taxes. The state government would like to decide if there is enough evidence to establish whether the proportion of citizens supporting an increase in cigarette taxes is significantly greater than .66. Identify the null hypothesis.

p  .66

p ≠ .66

p ≤ .66

 

 

In the upcoming election for governor, the most recent poll, based on 900 respondents, predicts that the incumbent will be reelected with 55 percent of the votes. From the 900 respondents, how many indicated that they would not vote for the current governor or indicated that they were undecided?

405

400

450

495

 

 

It has been reported that the average time to download the home page from a government website was 0.9 seconds. Suppose that the download times were normally distributed with a standard deviation of 0.3 seconds. If random samples of 36 download times are selected, calculate the mean of the sampling distribution of the sampling mean.

0.3

0.05

0.15

0.9

 

 

For a given hypothesis test, if we do not reject H0, and H0 is true,

no error has been committed.

a Type I error has been committed.

a Type II error has been committed.

a Type III error has been committed.

 

 

According to the Central Limit Theorem, if a sample size is at least _____, then for most sampled populations, we can conclude that the sample means are approximately normal.

50

25

20

30

 

 

If the sampled population distribution is skewed, then in most cases the sampling distribution of the mean can be approximated by the normal distribution if the sample size n is at least 30.

True

False

 

The sampling distribution of a sample statistic is the probability distribution of the population of all possible values of the sample statistic.

True

False

 

A(n) _____________ hypothesis is the statement that is being tested. It usually represents the status quo, and it is not rejected unless there is convincing sample evidence that it is false.

true

research

alternative

null

 

 

The diameter of small Nerf balls manufactured overseas is expected to be approximately normally distributed with a mean of 5.2 inches and a standard deviation of .08 inches. Suppose a random sample of 20 balls is selected. Calculate the mean of the sampling distribution of the sample mean.

0.8

5.2

0.08

0.018

 

If a population distribution is known to be normal, then it follows that

None of the other choices is correct.

the sample mean must equal the population mean.

the sample mean must equal the population mean, the sample mean must equal the population mean for large samples, and the sample standard deviation must equal the population standard deviation.

the sample standard deviation must equal the population standard deviation.

the sample mean must equal the population mean for large samples.

 

 

If p = .8 and n = 50, then we can conclude that the sampling distribution of     is approximately a normal distribution.

True

False

 

 

As the sample size increases, the standard deviation of the sampling distribution increases.

True

False

 

 

QNT 275 Week 5 Practice Connect Knowledge Check

A sequence of values of some variable or composite of variables taken at successive, uninterrupted time periods is called a

seasonal factor.

cyclical component.                        

moving average.

least squares (linear) trend line.

time series.

 

The chi-square goodness-of-fit is _________ a one-tailed test with the rejection region in the right tail.

never

sometimes

always

 

 

When the moving average method is used to estimate the seasonal factors with quarterly sales data, a ______ period moving average is used.

4

8

5

2

3

 

An experiment consists of 400 observations and four mutually exclusive groups. If the probability of a randomly selected item being classified into any of the four groups is equal, then the expected number of items that will be classified into group 1 is _____.

100

125

150

25

 

The range for r2 is between 0 and 1, and the range for r is between ____________.

There is no limit for r.

−1 and 0

0 and 1

−1 and 1

 

In simple regression analysis, the quantity that gives the amount by which Y (dependent variable) changes for a unit change in X (independent variable) is called the

correlation coefficient.

coefficient of determination.

slope of the regression line.

standard error.

y-intercept of the regression line.

 

The chi-square goodness-of-fit test will be valid if the average of the expected cell frequencies is ______________.

between 0 and 5

less than 5

at least 5

greater than 0

at least 1

 

Suppose that the unadjusted seasonal factor for the month of April is 1.10. The sum of the 12 months' unadjusted seasonal factor values is 12.18. The normalized (adjusted) seasonal factor value for April

cannot be determined with the information provided.

is equal to 1.1.

is larger than 1.1.

is smaller than 1.1.

 

One use of the chi-square goodness-of-fit test is to determine if specified multinomial probabilities in the null hypothesis are correct.

True

False

 

The slope of the simple linear regression equation represents the average change in the value of the dependent variable per unit change in the independent variable (X).

True

False

 

The upward or downward movement that characterizes a time series over a period of time is referred to as _____________.

irregular variation

seasonal variation

a trend

cyclical variation

 

A major drawback of the aggregate price index is that

it is difficult to compute.

percentage comparisons cannot be made to the base year.

it does not take into account the fact that some items in the market basket are purchased more frequently than others.

it is computed by using the values from a single time series or based on a single product.

 

The correlation coefficient may assume any value between

0 and 1.

0 and 8.

−1 and 1.

−1 and 0.

 

−∞ and ∞.

 

The number of degrees of freedom associated with a chi-square test for independence based upon a contingency table with 4 rows and 3 columns is _____.

5

7

12

6

In simple linear regression analysis, we assume that the variance of the independent variable (X) is equal to the variance of the dependent variable (Y).

 

True

False

hose fluctuations that are associated with climate, holidays, and related activities are referred to as __________ variations.

trend

cyclical

seasonal

irregular

 

A ______________________ measures the strength of the relationship between a dependent variable (Y) and an independent variable (X).

coefficient of determination

standard error

slope

correlation coefficient

When we carry out a chi-square test of independence, the chi-square statistic is based on (r × c) − 1 degrees of freedom, where r and c denote, respectively, the number of rows and columns in the contingency table.

True

False

 

The correlation coefficient is the ratio of explained variation to total variation.

True

False

 

A multinomial probability distribution describes data that are classified into two or more categories when a multinomial experiment is carried out.

 

True

False

 

The ____________________ is the proportion of the total variation in the dependent variable explained by the regression model.

correlation coefficient

slope

coefficient of determination

standard error

 

 

QNT 275 Week 5 Apply Connect Week 5 Case

You are the manager of a retail store. You want to investigate how metrics can improve the way you manage your business.

Use the Week 5 Data Set to create and calculate the following in Excel®:

Conduct a goodness of fit analysis which assesses orders of a specific item by size (expected) and items you received by size (observed).
Conduct a hypothesis test with the objective of determining if there is a difference between what you ordered and what you received at the .05 level of significance.
Identify the null and alternative hypotheses.
What is your conclusion?
Generate a scatter plot, the correlation coefficient, and the linear equation that evaluates whether a relationship exists between the number of times a customer visited the store in the past 6 months and the total amount of money the customer spent.
Set up a hypothesis test to evaluate the strength of the relationship between the two variables.
Use a level of significance of .05.
Use the regression line formula to forecast how much a customer might spend on merchandise if that customer visited the store 13 times in a 6 month period.
Consider the average monthly sales of 2014, $1310, as your base then
Calculate indices for each month for the next two years (based on the 24 months of data). 
Graph a time series plot.
In the Data Analysis Toolpak, use Excel's Exponential Smoothing option.
Apply a damping factor of .5, to your monthly sales data,  then create a new time series graph that compares the original and the revised monthly sales data. 
ORDERS VS. SHIPMENTS
 
Size
# Ordered
# Received
 
Extra Small
30
23
 
Small
50
54
 
Medium
85
92
 
Large
95
91
 
Extra Large
60
63
 
2X Large
45
42
 
CUSTOMERS IN PAST 6 MONTHS
Customer #
# Visits
$ Purchases
1
8
468
2
6
384
3
8
463
4
2
189
5
10
542
6
4
299
7
6
345
8
2
197
9
4
293
10
1
119
11
3
211
12
9
479
13
7
430
14
7
404
15
6
359
16
10
544
17
9
522
18
5
327
19
6
353
20
7
405
21
4
289
22
7
386
23
7
403
24
1
146
25
7
416
26
9
485
27
3
333
28
7
241
29
2
391
30
6
268
MONTHLY SALES ($)
 
Month
$ Sales
 
Jan
1375
 
Feb
1319
 
Mar
1222
 
Apr
1328
 
May
1493
 
Jun
1492
 
Jul
1489
 
Aug
1354
 
Sep
1530
 
Oct
1483
 
Nov
1450
 
Dec
1495
 
Jan
1545
 
Feb
1454
 
Mar
1322
 
Apr
1492
 
May
1678
 
Jun
1645
 
Jul
1580
 
Aug
1493
 
Sep
1719
 
Oct
1573
 
Nov
1629
 
Dec
1680
 
 
 
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