Question

A recent review of a compact disc distributor’s product line is summarized as follows:
Selling Price ($) Number of Titles Mean
0 to under 5 51 2.5
5 to under 10 184 7.5
10 to under 15 241 12.5
15 to under 20 1468 17.5
20 to under 25 1339 22.5
25 to under 30 255 27.5
30 to under 35 98 32.5
35 to under 40 14 37.5