PROBLEM 12E

Let p equal the proportion of yellow candies in a package of mixed colors. It is claimed that p = 0.20.

(a) Define a test statistic and critical region with a significance level of α = 0.05 for testing H0: p = 0.20 against a two-sided alternative hypothesis.

(b) To perform the test, each of 20 students counted the number of yellow candies, y, and the total number of candies, n, in a 48.1-gram package, yielding the following ratios, y/n: 8/56, 13/55, 12/58, 13/56, 14/57, 5/54,14/56, 15/57, 11/54, 13/55, 10/57, 8/59, 10/54, 11/55, 12/56, 11/57, 6/54, 7/58, 12/58, 14/58. If each individual tests H0: p = 0.20, what proportion of the students rejected the null hypothesis?

(c) If we may assume that the null hypothesis is true, what proportion of the students would you have expected to reject the null hypothesis?

(d) For each of the 20 ratios in part (b), a 95% confidence interval for p can be calculated. What proportion of these 95% confidence intervals contain p = 0.20?

(e) If the 20 results are pooled so that equals the total sample size, do we reject H0: p = 0.20?.

Chapter 8 - Hypothesis Testing ● Step 1: Restate the research question as a hypothesis with a null hypothesis about the populations ● make a claim about the population ○ the null hypothesis ○ H0 ● determine a relevant alternative claim ○ the alternative hypothesis ○ H1 ● Step 2: determine characteristics of the comparison distribution ○ represents the population situation if the null hypothesis is true ○ it is the distribution you are comparing your sample to ●