1. Economy. In 2008, a Gallup Poll asked 2336 U.S. adults, aged 18 or over, how they rated economic conditions. In a poll conducted from January 27 through February 1, 2008,
a) Does your confidence interval provide evidence to support the claim.
b) What is the significance level of the test in b? Explain.
2. Convenient alpha. An enthusiastic junior executive has run a test of his new marketing program. He reports that it resulted in a "significant" increase in sales. A footnote on his report explains that he used an alpha level of 7.2% for his test. Presumably, he performed a hypothesis test against the null hypothesis of no change in sales.
a) If instead he had used an alpha level of 5%, is it more or less likely that he would have rejected his null hypothesis? Explain.
b) If he chose the alpha level 7.2% so that he could claim statistical significance, explain why this is not an ethical use of statistics.