The numbers of minutes it took 12 students in a statistics class to complete the final exam are listed. Use a scatter plot to display this data set and the data set in Exercise 1. The data sets are in the same order. Describe any patterns. 

61   85   67   48   54   61   59   80   67   55   88   84

Data from exercise 1:

The overall averages of 12 students in a statistics class prior to taking the final exam are listed.

67   72   88   73   99   85   81   87   63   94  68   87

(a) Find the mean, median, and mode of the data set. Which best represents the center of the data?

(b) Find the range, variance, and standard deviation of the sample data set.

(c) Find the coefficient of variation of the data set.

(d) Display the data in a stem-and-leaf plot. Use one line per stem.