Question

9. Members at a popular fitness club currently pay $40 per month to be a member of the club. The owner of the club wants to raise the fee to $50 but is concerned that some members will quit if the fee increases. To investigate, the owner plans to survey a random sample of the members and construct a 95% confidence interval for the proportion of all members who would quit if the fee was increased to $50. (a) Explain the meaning of "95% confidence" in the context of the study. (b) After the owner conducted the survey, he calculated the confidence interval to be 0.18 0.075 Interpret this interval in the context of the study (c) According to the club's accountant, the fee increase will be worthwhile if fewer than 20% of the members quit. According to the interval from part (b), can the owner be confident that the fee increase will be worthwhile? Explain. (d) One of the conditions for calculating the confidence interval in part (b) is that and. Explain why it is necessary to check this condition. 10. A University of Illinois study on aggressive behavior surveyed a random sample of 558 middle school students. When asked to describe their behavior in the last 30 days, 445 students said their behavior included physical aggression, social idicule, teasing, name-calling, and issuing threats. Is this convincing evidence at the 5% level that more than three- arters of middle school students engage in this type of bullying behavior?

Answer 1