Recall from page 121 that 20 randomly selected customers give the following satisfaction ratings ( on a scale of 1 to 10) for a DVD recorder: 1, 3, 5, 5, 7, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 10, 10, 10, 10.

a. Using the technique discussed on page 119, find the first quartile, median, and third quartile for these data.

b. Do you obtain the same values for the first quartile and the third quartile that are shown on the MINITAB output in Figure 3.16 on page 121?

c. Using your results, construct a graphical display of a five- number summary and a box- and-whiskers display.