# Week 7 Quiz - Questions and Answers.docx - Question 1 0 7...

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Question 1 0 / 7 points The report of a sample survey of 1014 adults says, "with 95% confidence, between 9% and 15% of all Americans expect to spend more on gifts this year than last year." What does the phrase "95% confidence" mean? Question options: There is a 95% chance that the percent who expect to spend more is between 9% and 15%. 9% to 15% of all Americans will spend 95% of what they spent last year. 95% of all Americans will spend between 9% and 15% more than what they spent last year. The method used to get the interval 9% to 15%, when used over and over again, produces intervals which include the true population proportion 95% of the time.
Question 2 7 / 7 points What is the critical value of t for a 90% confidence interval with df = 14? (Assume a 2-tailed test) Question options:
Question 3 0 / 7 points What is the critical value for a 95% confidence interval based on a sample size of 20? (Population standard deviation is unknown). (Assume a 2-tailed test) Question options:
Question 4 7 / 7 points A survey of 30 random shoppers found a 95% confidence interval that shoppers will spend between \$24.50 and \$28.30. A second survey surveyed 25 random shoppers.