A survey of n = 1917 cell phone users in May 2010 asked ‘‘On an average day, about how many phone calls do you make and receive on your cell phone?” The results are displayed in Table A.5.

Number of Calls ..........Percentage
0 ............................................5%
1–5 ......................................44%
6–10 ....................................22%
11–20 ..................................14%
21–30 ....................................5%
More than 30 .......................6%
Don’t know ...........................3%

(a) What is the sample? What is the intended population?
(b) Is this a frequency table or a relative frequency table?
(c) We can’t draw an accurate histogram from the data in the table since the first category has a single value and the last is unbounded (even if we ignore the nonresponses). However, you should still be able to discuss the general shape of the distribution. For example, are the data skewed or relatively symmetric? Explain your reasoning.
(d) The article lists two statistics for the ‘‘center” of these data: 5.00 and 13.10. Which is the mean and which is the median? Explain.