7.65 Sample versus sampling Each student should bring 10 coins to class. For each coin, observe its age, the difference between the current year and the year on the coin.

a. Using all the students’ observations, the class should construct a histogram of the sample ages. What is its shape?

b. Now each student should find the mean for that student’s 10 coins, and the class should plot the means of all the students. What type of distribution is this, and how does it compare to the one in part a? What concepts does this exercise illustrate?