The report “Testing the Waters 2009” (www

.nrdc.org) included information on the water quality at the 82 most popular swimming beaches in California.

Thirty-eight of these beaches are in Los Angeles County.

For each beach, water quality was tested weekly and the data below are the percent of the tests in 2008 that failed to meet water quality standards.

Los Angeles County 32 4 6 4 4 7 4 27 19 23 19 13 11 19 9 11 16 23 19 16 33 12 29 3 11 6 22 18 31 43 17 26 17 20 10 6 14 11 Other Counties 0 0 0 2 3 7 5 11 5 7 15 8 1 5 0 5 4 1 0 1 1 027022353 0 8 8 8 0 0 17 4 3 7 10 40 3

a. Construct a dotplot of the percent of tests failing to meet water quality standards for the Los Angeles County beaches. Write a few sentences describing any interesting features of the dotplot.

b. Construct a dotplot of the percent of tests failing to meet water quality standards for the beaches in other counties. Write a few sentences describing any interesting features of the dotplot.

c. Based on the two dotplots from Parts

(a) and (b), describe how the percent of tests that fail to meet water quality standards for beaches in Los Angeles county differs from those of other counties.