Example 3.19 used annual rainfall data for Albuquerque, New Mexico, to construct a relative frequency distribution and cumulative relative frequency plot. The National Climate Data Center also gave the accompanying annual rainfall (in inches) for Medford, Oregon, from 1950 to 2008. 28.84 20.15 18.88 25.72 16.42 20.18 28.96 20.72 23.58 10.62 20.85 19.86 23.34 19.08 29.23 18.32 21.27 18.93 15.47 20.68 23.43 19.55 20.82 19.04 18.77 19.63 12.39 22.39 15.95 20.46 16.05 22.08 19.44 30.38 18.79 10.89 17.25 14.95 13.86 15.30 13.71 14.68 15.16 16.77 12.33 21.93 31.57 18.13 28.87 16.69 18.81 15.15 18.16 19.99 19.00 23.97 21.99 17.25 14.07

a. Construct a relative frequency distribution for the Medford rainfall data.

b. Use the relative frequency distribution of Part

(a) to construct a histogram. Describe the shape of the histogram.

c. Construct a cumulative relative frequency plot for the Medford rainfall data.

d. Use the cumulative relative frequency plot of Part (c)

to answer the following questions:

i. Approximately what proportion of years had annual rainfall less than 15.5 inches?

ii. Approximately what proportion of years had annual rainfall less than 25 inches?

iii. Approximately what proportion of years had annual rainfall between 17.5 and 25 inches?