Written Assignment
1. We are interested in looking at the balance in a bank account after looking at all the deposits and withdrawals. This is an example of a variable that is measured by the:
a. ratio scale
b. interval scale
c. nominal scale
d. ordinal scale
2. The speeds of 18 roller coasters around the U.S. are listed below:
|
Roller Coaster
|
Speed
|
|
1
|
81
|
|
2
|
45
|
|
3
|
76
|
|
4
|
76
|
|
5
|
89
|
|
6
|
32
|
|
7
|
36
|
|
8
|
100
|
|
9
|
105
|
|
10
|
81
|
|
11
|
81
|
|
12
|
34
|
|
13
|
90
|
|
14
|
89
|
|
15
|
89
|
|
16
|
57
|
|
17
|
138
|
|
18
|
89
|
a. Is this type of data categorical or quantitative? If quantitative, is it discrete or continuous?
b. Calculate the number of classes and class width.
c. Construct a frequency distribution, including the relative frequency.
d. Construct a histogram or bar graph (depending on your answer to part a), including all labels.
e. Calculate the mean, median, and mode.
f. Are the mean, median, and mode descriptive or inferential statistics?
g. Calculate the range and IQR.
h. Find the standard deviation.
i. Find the coefficient of variation.
j. What is the 60th percentile of this data set?
k. Does this data set have any outliers? Use statistics in answering this question (not just your opinion).
l. Would you use the Empirical rule or Chebyshev's Theorem here and why?
m. Based on the mean and median calculated above, would you expect this data to be symmetric, skewed to the left or skewed to the right and why?
3. A survey of 700 college students resulted in the following cross tabulation regarding if they exercise or not and whether or not they sleep the recommended 8 hours a night.
|
Sleep at least 8 hours
|
|
Exercise
|
Yes
|
No
|
Total
|
|
Yes
|
120
|
140
|
260
|
|
No
|
280
|
160
|
440
|
|
Total
|
400
|
300
|
700
|
a. Of the students surveyed who exercise, what percentage also sleep at least 8 hours a night?