Donald Heel is the Microwave Oven Division Manager of Sharp Products. Don proposes a $40 cash rebate program as a means of promoting Sharp€™s new crisp-broil-and-grill microwave oven. However, Sharp€™s president wants evidence that the program would increase sales by at least 25%, so Don applies some of his research budget to a survey. He uses National Phone Systems Company to conduct a nationwide survey using random digit dialing. National Phone Systems is a fully integrated telephone polling company, and it has the capability of providing daily tabulations. Don decides to use this option, and instead of specifying a final sample size, he chooses to have National Phone Systems perform 50 completions each day. At the end of five days of field work, the daily results are as follows:

For how much longer should Don continue the survey? Indicate your rationale.

Transcribed Image Text:

Day Total Sample Size Percent ofrespondents who 2 4 50 100 150 200250 ould consider buying a Sharp microwave with a S40 rebate 50% 40% 35% 30% 33%