A study found that 51 children who watched a commercial for Walker Crisps ( potato chips) featuring a long-standing sports celebrity endorser ate a mean of 36 grams of Walker Crisps as compared to a me an of 25 grams of Walker Crisps for 41 children who watched a commercial for an alternative food snack .
Suppose that the sample standard deviation for the children who watched the sports celebrity-endorsed Walker Crisps commercial was 21.4 grams a nd the sample standard deviation for the children who watched the alternative food snack commercial was 12.8 grams.
a. Assuming that the population variances are equal and a = 0 .05, is the re evidence that the mean amount of Walker Crisps eaten was significantly higher for the children who watched the sports celebrity-endorsed Walker Crisps commercial?
b. Assuming that the population variances are equal, construct a 95 % confidence interval estimate of the difference be tween the mean amount of Walker Crisps eaten by children who watched the sports celebrity-endorsed Walker Crisps commercial and children w ho watched the alternative food snack commercial.
c. Compare and discuss the results of (a) and (b).
d . Based on the results of (a) and (b), if you wanted to increase the consumption of Walker Crisps , which commercial would you choose?