# What is (are) the most widely used measure(s) of dispersion?

QNT 275 Entire Course Link

https://uopcourses.com/sd_product/qnt-275-week-5-final-examination/

QNT 275 Week 5 Final Examination

Click the link to the Final Examination.

Complete the Final Examination.

You are allowed one attempt to complete the exam, which is timed and must be completed in 3 hours. Results are auto graded and sent to your instructor.

***The questions of final exam are totally the same. Just the sequence is different.***

1

The salaries of teachers in a particular school district are normally distributed with a mean of $50,000 and a standard deviation of $2,500. Due to budget limitations, it has been decided that the teachers who are in the top 2.5% of the salaries would not get a raise. What is the salary level that divides the teachers into one group that gets a raise and one that doesn’t?

45,100

54,900

-1.96

1.96

2

In the accompanying stem-and-leaf diagram, the values in the stem and leaf portions represent 10s and 1s digits, respectively.

The stem-and-leaf diagram shows that the distribution is ___________.

None of the answers

negatively skewed

symmetric

positively skewed

3

Which of the following is a quantitative variable?

House age

All the answers

House price

House size

4

Which of the following meets the requirements of a stratified random sample?

A population contains 10 members under the age of 25 and 20 members over the age of 25. The sample will include six males chosen at random, without regard to age.

A population contains 10 members under the age of 25 and 20 members over the age of 25. The sample will include six people who volunteer for the sample.

A population contains 10 members under the age of 25 and 20 members over the age of 25. The sample will include six people chosen at random, without regard to age.

A population contains 10 members under the age of 25 and 20 members over the age of 25. The sample will include two people chosen at random under the age of 25 and four people chosen at random over 25.

5

Which of the following can be represented by a continuous random variable?

The number of typos found on a randomly selected page of this test bank

The average temperature in Tampa, Florida, during the month of July

The number of customers who visit a department store between 10:00 a.m. and 11:00 a.m. on Mondays

The number of students who will get financial assistance in a group of 50 randomly selected students

6

In the sample regression equation what is ?

The y-intercept

The predicted value of y, given a specific x value

The value of y when x = 0

The slope of the equation

7

Mutually exclusive events ______________.

do not share common outcomes

contain all possible outcomes

do not contain all possible outcomes

may share common outcomes

8

Which of the following can be represented by a discrete random variable?

The circumference of a randomly generated circle

The average distance achieved in a series of long jumps

The number of defective light bulbs in a sample of five

The time of a flight between Chicago and New York

9

A manager of a fast food restaurant wants to ensure that staff are scheduled with the sufficient hours required to meet customer demands without overspending on labor costs. The manager has daily guest counts, sales data, and staff hours for the prior year. What should the manager do next in order to reach conclusions about scheduling restaurant staff?

Provide the data sets to the restaurant owner for analysis by the owner’s staff.

Schedule staff based on the staffing levels used on the same date the prior year.

Perform descriptive statistics, inferential statistics, and time series analysis.

Create a graph of the data and extend the graph forward in time to set the schedule.

10

A-Plus Dry Cleaners wants to understand its customers’ perceptions of the quality of the company’s customer service. They plan to survey a sample of its customer base. What will A-Plus need to do to ensure that their data is valid and reliable?

The survey must include items that ask customers to rate the appearance of the dry cleaning store, the survey must include all customers, and the survey method must include setting up a table outside the local dollar store.

The survey must include items that ask customers to rate the quality of the company’s customer service, the survey sample must represent all parts of the customer population, and the survey method must be repeatable.

The survey must include items that ask customers to rate the friendliness of the staff, the survey must include all customers from the north side of the city, and the survey method must appeal to all respondents.

The survey must include items that ask customers about their dry cleaning experiences, the survey sample must include the first 15 customers off the customer database, and the survey method must be repeatable.

11

The two branches of the study of statistics are generally referred to as ___________.

differential and descriptive statistics

inferential and differential statistics

descriptive and referential statistics

descriptive and inferential statistics

12

Serial correlation is typically observed in:

time series data

outliers

sparse data

cross-sectional data

13

The manager of a retail shoe store has applied statistics to analyze sales, purchasing, and data and reached the conclusion that the store could reduce costs by reducing inventory of very small and very large sizes, and substituting an online ordering service to drop-ship rare sizes directly from suppliers. How should the manager communicate those results to the store owner?

Summarize the recommendations, supported by visual representation of the data and statistics.

Schedule a conference call with the owner and suppliers to discuss online ordering options.

Project the future online sales data using a line graph.

Provide the complete data set and all statistical analyses to the owner in spreadsheets.

14

Professors at a local university earn an average salary of $80,000 with a standard deviation of $6,000. The salary distribution is approximately bell-shaped. What can be said about the percentage of salaries that are at least $74,000?

About 84 percent

About 97.5 percent

About 95 percent

About 68 percent

15

Which of the following violates the assumptions of regression analysis?

The error term has a constant variance.

The error term is uncorrelated with an explanatory variable.

The error term has a zero mean.

The error term does not have the normal distribution.

16

The study of statistics can be defined as:

the language of data.

the art and science of getting information from data.

All of the answers

the study of collecting, analyzing, presenting, and interpreting data.

17

What is the name of the variable that’s used to predict another variable?

Coefficient of determination

Response

Explanatory

Standard error of the estimate

18

Consider a population with data values of 12, 8, 28, 22, 12, 30, 14.

The median is:

12

22

14

18

19

Which scales of data measurement are associated with quantitative data?

Nominal and ordinal

Ordinal and interval

Ratio and nominal

Interval and ratio

20

What is (are) the most widely used measure(s) of dispersion?

Covariance and the correlation coefficient

Interquartile range

Variance and standard deviation

Range

21

Frequency distributions may be used to describe which of the following types of data?

Nominal and interval data only

Nominal, ordinal, and interval data only

Nominal and ordinal data only

Nominal, ordinal, interval, and ratio data

22

A company wants to estimate the mean price of oil over the past 10 years. What kind of data does the company need?

Descriptive statistics

Cross-sectional data

Time series data

Inferential statistics

23

What type of relationship is indicated in the scatterplot?

A negative linear relationship

A positive linear or curvilinear relationship

A negative curvilinear relationship

No relationship

24

Which of the following is most influenced by outliers?

75th percentile

Mean

Mode

Median

25

Bias can occur in sampling. Bias refers to _____________________.

the division of the population into overlapping groups

the creation of strata, which are proportional to the stratum’s size

the use of cluster sampling instead of stratified random sampling

the tendency of a sample statistic to systematically over-or underestimate a population parameter

26

The owner of a company has recently decided to raise the salary of one employee, who was already making the highest salary, by 20%. Which of the following is(are) expected to be affected by this raise?

Median only

Mean, median, and mode

Mean and median only

Mean only

27

The estimation of which of the following requires sampling?

The Cleveland Indians’ hitting percentage in 2010

The average SAT score of incoming freshmen at a university

U.S. unemployment rate

Total rainfall in Phoenix, Arizona, in 2010

28

Horizontal bar charts are constructed by placing:

each interval of values on the vertical axis and the appropriate range of values on the horizontal axis.

each category on the horizontal axis and the appropriate range of values on the vertical axis.

each category on the vertical axis and the appropriate range of values on the horizontal axis.

None of the Answers.

29

A hedge fund returns on average 26% per year with a standard deviation of 12%. Using the empirical rule, approximate the probability the fund returns over 50% next year.

0.5%

1%

5%

2.5%

https://uopcourses.com/sd_product/qnt-275-week-5-final-examination/

QNT 275 Week 5 Final Examination

Click the link to the Final Examination.

Complete the Final Examination.

You are allowed one attempt to complete the exam, which is timed and must be completed in 3 hours. Results are auto graded and sent to your instructor.

***The questions of final exam are totally the same. Just the sequence is different.***

1

The salaries of teachers in a particular school district are normally distributed with a mean of $50,000 and a standard deviation of $2,500. Due to budget limitations, it has been decided that the teachers who are in the top 2.5% of the salaries would not get a raise. What is the salary level that divides the teachers into one group that gets a raise and one that doesn’t?

45,100

54,900

-1.96

1.96

2

In the accompanying stem-and-leaf diagram, the values in the stem and leaf portions represent 10s and 1s digits, respectively.

The stem-and-leaf diagram shows that the distribution is ___________.

None of the answers

negatively skewed

symmetric

positively skewed

3

Which of the following is a quantitative variable?

House age

All the answers

House price

House size

4

Which of the following meets the requirements of a stratified random sample?

A population contains 10 members under the age of 25 and 20 members over the age of 25. The sample will include six males chosen at random, without regard to age.

A population contains 10 members under the age of 25 and 20 members over the age of 25. The sample will include six people who volunteer for the sample.

A population contains 10 members under the age of 25 and 20 members over the age of 25. The sample will include six people chosen at random, without regard to age.

A population contains 10 members under the age of 25 and 20 members over the age of 25. The sample will include two people chosen at random under the age of 25 and four people chosen at random over 25.

5

Which of the following can be represented by a continuous random variable?

The number of typos found on a randomly selected page of this test bank

The average temperature in Tampa, Florida, during the month of July

The number of customers who visit a department store between 10:00 a.m. and 11:00 a.m. on Mondays

The number of students who will get financial assistance in a group of 50 randomly selected students

6

In the sample regression equation what is ?

The y-intercept

The predicted value of y, given a specific x value

The value of y when x = 0

The slope of the equation

7

Mutually exclusive events ______________.

do not share common outcomes

contain all possible outcomes

do not contain all possible outcomes

may share common outcomes

8

Which of the following can be represented by a discrete random variable?

The circumference of a randomly generated circle

The average distance achieved in a series of long jumps

The number of defective light bulbs in a sample of five

The time of a flight between Chicago and New York

9

A manager of a fast food restaurant wants to ensure that staff are scheduled with the sufficient hours required to meet customer demands without overspending on labor costs. The manager has daily guest counts, sales data, and staff hours for the prior year. What should the manager do next in order to reach conclusions about scheduling restaurant staff?

Provide the data sets to the restaurant owner for analysis by the owner’s staff.

Schedule staff based on the staffing levels used on the same date the prior year.

Perform descriptive statistics, inferential statistics, and time series analysis.

Create a graph of the data and extend the graph forward in time to set the schedule.

10

A-Plus Dry Cleaners wants to understand its customers’ perceptions of the quality of the company’s customer service. They plan to survey a sample of its customer base. What will A-Plus need to do to ensure that their data is valid and reliable?

The survey must include items that ask customers to rate the appearance of the dry cleaning store, the survey must include all customers, and the survey method must include setting up a table outside the local dollar store.

The survey must include items that ask customers to rate the quality of the company’s customer service, the survey sample must represent all parts of the customer population, and the survey method must be repeatable.

The survey must include items that ask customers to rate the friendliness of the staff, the survey must include all customers from the north side of the city, and the survey method must appeal to all respondents.

The survey must include items that ask customers about their dry cleaning experiences, the survey sample must include the first 15 customers off the customer database, and the survey method must be repeatable.

11

The two branches of the study of statistics are generally referred to as ___________.

differential and descriptive statistics

inferential and differential statistics

descriptive and referential statistics

descriptive and inferential statistics

12

Serial correlation is typically observed in:

time series data

outliers

sparse data

cross-sectional data

13

The manager of a retail shoe store has applied statistics to analyze sales, purchasing, and data and reached the conclusion that the store could reduce costs by reducing inventory of very small and very large sizes, and substituting an online ordering service to drop-ship rare sizes directly from suppliers. How should the manager communicate those results to the store owner?

Summarize the recommendations, supported by visual representation of the data and statistics.

Schedule a conference call with the owner and suppliers to discuss online ordering options.

Project the future online sales data using a line graph.

Provide the complete data set and all statistical analyses to the owner in spreadsheets.

14

Professors at a local university earn an average salary of $80,000 with a standard deviation of $6,000. The salary distribution is approximately bell-shaped. What can be said about the percentage of salaries that are at least $74,000?

About 84 percent

About 97.5 percent

About 95 percent

About 68 percent

15

Which of the following violates the assumptions of regression analysis?

The error term has a constant variance.

The error term is uncorrelated with an explanatory variable.

The error term has a zero mean.

The error term does not have the normal distribution.

16

The study of statistics can be defined as:

the language of data.

the art and science of getting information from data.

All of the answers

the study of collecting, analyzing, presenting, and interpreting data.

17

What is the name of the variable that’s used to predict another variable?

Coefficient of determination

Response

Explanatory

Standard error of the estimate

18

Consider a population with data values of 12, 8, 28, 22, 12, 30, 14.

The median is:

12

22

14

18

19

Which scales of data measurement are associated with quantitative data?

Nominal and ordinal

Ordinal and interval

Ratio and nominal

Interval and ratio

20

What is (are) the most widely used measure(s) of dispersion?

Covariance and the correlation coefficient

Interquartile range

Variance and standard deviation

Range

21

Frequency distributions may be used to describe which of the following types of data?

Nominal and interval data only

Nominal, ordinal, and interval data only

Nominal and ordinal data only

Nominal, ordinal, interval, and ratio data

22

A company wants to estimate the mean price of oil over the past 10 years. What kind of data does the company need?

Descriptive statistics

Cross-sectional data

Time series data

Inferential statistics

23

What type of relationship is indicated in the scatterplot?

A negative linear relationship

A positive linear or curvilinear relationship

A negative curvilinear relationship

No relationship

24

Which of the following is most influenced by outliers?

75th percentile

Mean

Mode

Median

25

Bias can occur in sampling. Bias refers to _____________________.

the division of the population into overlapping groups

the creation of strata, which are proportional to the stratum’s size

the use of cluster sampling instead of stratified random sampling

the tendency of a sample statistic to systematically over-or underestimate a population parameter

26

The owner of a company has recently decided to raise the salary of one employee, who was already making the highest salary, by 20%. Which of the following is(are) expected to be affected by this raise?

Median only

Mean, median, and mode

Mean and median only

Mean only

27

The estimation of which of the following requires sampling?

The Cleveland Indians’ hitting percentage in 2010

The average SAT score of incoming freshmen at a university

U.S. unemployment rate

Total rainfall in Phoenix, Arizona, in 2010

28

Horizontal bar charts are constructed by placing:

each interval of values on the vertical axis and the appropriate range of values on the horizontal axis.

each category on the horizontal axis and the appropriate range of values on the vertical axis.

each category on the vertical axis and the appropriate range of values on the horizontal axis.

None of the Answers.

29

A hedge fund returns on average 26% per year with a standard deviation of 12%. Using the empirical rule, approximate the probability the fund returns over 50% next year.

0.5%

1%

5%

2.5%

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