A question in the 2002 General Social Survey (GSS) conducted by the National Opinion Research Center asked participants how long they spend on e-mail each week. A summary of responses (hours) for n = 1881 respondents follows. (The data are in the dataset GSS-02 on the companion website.)
|
Mean
|
StdDev
|
Minimum
|
Q1
|
Median
|
Q3
|
Maximum
|
|
4.14
|
7.235
|
0
|
0
|
2
|
5
|
70
|
a. Explain how the summary statistics show us that at least 25% of the respondents said that they do not use e-mail.
b. What is the interval that contains the lower 50% of the responses?
c. What is the interval that contains the upper 50% of the responses?
d. Explain whether or not the maximum value, 70 hours, would be marked as an outlier on a boxplot.
e. Calculate Range/6 and compare the answer to the value of the standard deviation. What feature(s) of the data do you think causes the values to differ?
f. Compare the mean to the median. What feature(s) of the data do you think causes the values to differ?