The frequency distribution representing the number of frequent flier miles accumulated by employees at Brumley Statistical Consulting Inc. is repeated from Exercise 17.
Frequent Flier Miles
(000) Frequency
0 up to 3 ........... 5
3 up to 6 ........... 12
6 up to 9 ........... 23
9 up to 12........... 8
12 up to 15........... 2
Total ............ 50

a. How many employees accumulated less than 3,000 miles?
b. Convert the frequency distribution to a cumulative frequency distribution.
c. Portray the cumulative distribution in the form of a cumulative frequency polygon.
d. Based on the cumulative frequency polygon, about 75% of the employees accumulated how many miles or less?