10.144 [EX10-144] Sucrose, ordinary table sugar, is probably the single most abundant pure organic chemical in the world and the one most widely known to nonchemists. Whether from sugar cane

(20% by weight) or sugar beets (15% by weight), and whether raw or refined, common sugar is still sucrose. Fifteen U.S. sugar beet–producing counties were randomly selected and their 2001 sucrose percentages recorded. Similarly, twelve U.S. sugar cane–producing counties were randomly selected and their 2001 sucrose percentages recorded.

SBsucrose 17.30 16.46 16.20 17.53 17.00 18.53 16.77 16.11 15.30 17.90 15.98 17.30 17.94 17.30 16.60 SCsucrose 14.1 13.5 15.2 15.0 13.6 13.6 11.7 14.3 13.8 13.8 14.8 13.7 Source: http://www.usda.gov/nass/graphics/county01/data/
Find the 95% confidence interval for the difference between the mean sucrose percentage for all U.S. sugar beet–producing counties and all U.S.
sugar cane–producing counties. Assume normality.