# QNT 275 Week 1 Practice Set

QNT 275 Week 1 Practice Set

Complete the Week 1 Practice Set problems.

Click the Assignment Files tab to submit your assignment.

Practice Set 1

Practice Set 1

The following table lists the number of deaths by cause as reported by the Centers for Disease Control and Prevention on February 6, 2015:

Cause of Death
Number of Deaths
Heart disease
611,105
Cancer
584,881
Accidents
130,557
Stroke
128,978
Alzheimer’s disease
84,767
Diabetes
75,578
Influenza and Pneumonia
56,979
Suicide
41,149

What is the variable for this data set (use words)?

How many observations are in this data set (numeral)?

How many elements does this data set contain (numeral)?

Indicate which of the following variables are quantitative and which are qualitative.

Note: Spell quantitative and qualitative in lower case letters.

The amount of time a student spent studying for an exam

The amount of rain last year in 30 cities

The arrival status of an airline flight (early, on time, late, canceled) at an airport

A person’s blood type

The amount of gasoline put into a car at a gas station

A local gas station collected data from the day’s receipts, recording the gallons of gasoline each customer purchased. The following table lists the frequency distribution of the gallons of gas purchased by all customers on this one day at this gas station.

Gallons of Gas
Number of Customers
4 to less than 8
78
8 to less than 12
49
12 to less than 16
81
16 to less than 20
117
20 to less than 24
13

How many customers were served on this day at this gas station?

Find the class midpoints. Do all of the classes have the same width? If so, what is this width? If not, what are the different class widths?

What percentage of the customers purchased between 4 and 12 gallons? (do not include % sign. Round numerical value to one decimal place)

The following data give the one-way commuting times (in minutes) from home to work for a random sample of 50 workers.

23
17
34
26
18
33
46
42
12
37
44
15
22
19
28
32
18
39
40
48
16
11
9
24
18
26
31
7
30
15
18
22
29
32
30
21
19
14
26
37
25
36
23
39
42
46
29
17
24
31

What is the frequency for each class 0–9, 10–19, 20–29, 30–39, and 40–49.

Calculate the relative frequency and percentage for each class.

What percentage of the workers in this sample commute for 30 minutes or more?

Note: Round relative frequency to two decimal places. Complete the table by calculating the frequency, relative frequency, and percentage.

Commuting Times

Frequency

(part a)

Relative Frequency

(part c)
Percentage (%)

(part d)
0-9
?
0.??
?
10-19
?
0.??
?
20-29
?
0.??
?
30-39
?
0.??
?
40-49
?
0.??
?

The following data give the number of text messages sent on 40 randomly selected days during 2015 by a high school student.

32
33
33
34
35
36
37
37
37
37
38
39
40
41
41
42
42
42
43
44
44
45
45
45
47
47
47
47
47
48
48
49
50
50
51
52
53
54
59
61

Each stem has been displayed (left column). Complete this stem-and-leaf display for these data.

Note: Use a space in between each leaf. For example 1 2 3 4 5 6 7 8 9 (do not use this format 123456789).

3
?…

4
?…

5
?…

6
?…

6 A) Which of the five measures of center (the mean, the median, the trimmed mean, the weighted mean, and the mode) can be calculated for quantitative data only.

B) Which can be calculated for both quantitative and qualitative data?

Prices of cars have a distribution that is skewed to the right with outliers in the right tail. Which of the measures of center is the best to summarize this data set?

The following data give the amounts (in dollars) of electric bills for November 2015 for 12 randomly selected households selected from a small town.

205
265
176
314
243
192
297
357
238
281
342
259

Calculate the (a) mean, (b) median and (c) Is there a mode (Yes or No)?

The following data give the prices of seven textbooks randomly selected from a university bookstore.

\$89
\$170
\$104
\$113
\$56
\$161
\$147

a) Find the mean for these data (input the numerical value without the dollar sign). Calculate the deviations of the data values from the mean.

b) Is the sum of these deviations zero (yes or no)?

c) Calculate the range (do not include unit).

d) Calculate the variance.

e) Calculate the standard deviation (round to one decimal place).

The following data give the speeds of 13 cars (in mph) measured by radar, traveling on I-84.

73
75
69
68
78
69
74
76
72
79
68
77
71

Find the values of the three quartiles and the interquartile range.

Calculate the (approximate) value of the 35th percentile (round to two decimal places).

Compute the percentile rank of 71 (round to two decimal places. Do not include the % symbol).

Note: Round to two decimal places. Do not include unit.