A 20-minute consumer survey mailed to 500 adults aged 25-34 included a $5 Starbucks gift certificate. The same survey was mailed to 500 adults aged 25-34 without the gift certificate. There were 65 responses from the first group and 45 from the second group.
(a) Perform a two tailed test comparing the response rate (proportions) at a = .05
(b) Form a confidence interval for the difference of proportions, without pooling the sample. Does it includes zero?
Please see the attached file.
Hypotheses: H0: p1 = p2 vs. HA: p1 ≠ p2
Level of Significance: a = 5%
Decision Rule: Reject the null hypothesis if p-value < ...
The solution examines a Starbucks consumers survey by using a two tailed test to compare the response rate.