Question

There is no Dana, only Zeul (Who you gonna call). In November of 2005 the Harris Poll asked 889 (a) In constructing confidence intervals, would we use z ort in this situation? Briefly explain why (b) Estimate p the true proportion of US adults that believe in ghosts, with 90% confidence. Interpret (c) Suppose, using the information from the survey (the 29% that believe in ghosts) that a new survey randomly selected US adults, "Do you believe in ghosts?" 29% said they did. you would use one instead of the other. the interval in context of the data. is to be taken and the new bound is to be 2%. What sample size will be required? (d) Suppose that we know nothing of any prior results from this study (thus have no estimate for the proportion of those US adults that believe in ghosts). What proportion should we use for the estimation? What sample size do we need with no prior information? Why is it different than the sample size from part (c)? (e) Previous polls have the percent of people that believe in ghosts at 33%. Is there sufficient evidence that the proportion of people who believe in ghosts is less that what previous polls indicate? Complete a hypothesis test; show all steps. (f) Based on the results of the hypothesis test, what kind of error could have been made (in context)?

Answer 1

Sol:
Date Poge ven hati-m 889 we use z-test, because Sample size is arge 4 le proporhon Unknaun The 9o'la Com fidanre intenal forP 0.29 +(1.645) | (0.23)(-) 883 29 +0645)(o:ois2) 0.29 o 025D O.265 O.315

-0.02 (2% maxgin ufena PCI-P) O-02-1, 6457 |e.29)(0キ1) 0.02 Size三) 3gろレー = 41,13 diffrent.干っ C -because-pis diffre nt.