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Question 8 --/1 View Policies Current Attempt in Progress How Many Close Confidants Do People Have? In a recent study,1 2006 randomly selected US adults (age 18 or older) were asked to give the number of people in the last six months "with whom you discussed matters that are important to you." The average number of close confidants was 2.2, with a standard deviation of 1.4. 1 Hampton, K., Goulet, L., Rainie, L., and Purcell, K., “Social Networking Sites and Our Lives." Pew Research Center, pewresearch.org, June 16, 2011. (a) Find the margin of error for this estimate if we want 95% confidence. Round your answer to three decimal places. margin of error = i e Textbook and Media (b) Find a 95% confidence interval for average number of close confidants. Round your answers to three decimal places. The 95% confidence interval is i to i e Textbook and Media Attempts: 0 of 3 used Save for Later Submit Answer

Answer 1

Given sample size n=2006 Mean of sample data x = 2.2 Sample standard deviation s= 1.4 95% confidence level z-score z=1.96 a) Margin of error=2* = 1.96 * 2.= 0.0613~0.061 b) 95% confidence interval for mean is as follows = (8= 2* + 2* = (2.2-1.96 * 2006; 2.2+1.96 * 2006 = (2.1387, 2.2613) 95% confidence interval= (2.1387, 2.2613)