A 20-minute consumer survey that included a $5 Starbucks gift card was emailed to 500 adults aged 25-34. The survey resulted in 65 responses. The same 20-minute consumer survey was emailed to 500 adults aged 25-34 without the Starbucks gift card. The survey resulted in 45 responses. We would like to know if the inclusion of a Starbucks gift card led to any change in survey response rate. Which of the following hypotheses should be used? A. Null Hypothesis: mul (average number of responses with Starbucks gift card)<= muo(average number of responses without Starbucks gift card) Alternative Hypothesis: mu1 ( average number of responses with Starbucks gift card)> muo(average number of responses without Starbucks gift card)
B. Null Hypothesis: mu1 (average number of responses with Starbucks gift card)= mud (average number of responses without Starbucks gift card) Alternative Hypothesis: mu1 ( average number of responses with Starbucks gift card) \= mul ( average number of responses without Starbucks gift card) * \= means "not equal to"
C. Null Hypothesis: pi1 (rate with Starbucks gift card)= pi2 (rate without Starbucks gift card) Alternative Hypothesis: pi1 (rate with Starbucks gift card) (= pi2 (rate without Starbucks gift card) * \= means "not equal to"
D. Null Hypothesis: pi1 (rate with Starbucks gift card) - pi2 (rate without Starbucks gift card)<=0 Alternative Hypothesis: pi1 (rate with Starbucks gift card) - pi2 (rate without Starbucks gift card) > 0