Question

12 of 13 ID: MST.CI.CIP.01.0030.STAT301 [1 point] A statistics lecturer poses the following question to her students as homework: 'Suppose I collected a sample and calculated the sample proportion. If I construct a 90% confidence interval for the population proportion and a 95% confidence interval for the population proportion, which of these intervals will be wider?' Three students provide their answers as follows: Tim: 'The 90% confidence interval will be wider.' Trevor: 'The 95% confidence interval will be wider.' Tracy: 'There is not enough information to tell. Either interval could be wider.' The student that is correct is: Tim Trevor O Tracy - 13 of 13 ID: MST.FET.E.CIP.02.0010A [2 points] A survey was run by a high school student in order to determine what proportion of mortgage-holders in his town expect to own their house within 10 years. He surveyed 36 mortgage holders and found that the proportion of these that did expect to own their house within 10 years is 0.64. The student decides to construct a 95% confidence interval for the population proportion. a) Calculate the margin of error that the high school student will have. Give your answer as a decimal to 2 decimal places. Margin of error = A university student finds the survey results of the high school student and believes he should have had a larger sample. The university student surveys 72 mortgage holders in her town and finds that the proportion of these that do expect to own their house within 10 years is again 0.64. This student also constructs a 95% confidence interval for the population proportion. b) Calculate the margin of error that the university student will have. Give your answer as a decimal to 2 decimal places. Margin of error =

Answer 1

solution :- 12) B Trevor (as we increase contidence level Me increase, so width become wider Ispritzo toonid 13) 7912 Þ (-Ê a) ME = to miorell 1.96 O, 64 x 0.36 36 0.16 Doba bidalge b) now GELA 72 ME = 1.968 0.64 x 0.36 72 ME