samp orde (3.307, 4.859) 60 0.388 4.1 3.0 News mea = 7, where u is the population a. Is it plausible that u mean for all Florida students? Explain. of $ а. I- b. Suppose that the sample size had been 240, with x=4.1 and s = 3.0. Finda 95% confidence interval and compare it to the one reported. Describe the effect of sample size on the margin of error. V b.F c. Does it seem plausible that the population distribution of this variable is normal? Why? tl lc d. Explain the implications of the term robust regard- ing the normality assumption made to conduct this analysis. t 8.45 Nun chilc СЕСH .ber 8.40 Political views The General Social Survey asks respondents to rate their political views on a seven-point scale, where 1 = sam extremely liberal, 4 = moderate, and (Us und "eig 7= extremely conservative. A researcher analyzing data from the 2012 GSS obtains MINITAB output: a. S 95% CI St Dev SE Mean Variable Mean POLVIEWS 1874 4.0624 1.4529 0.0336 (3.9965, 4.1283) b. C a. Show how to construct the confidence interval from the other information provided. b. Can you conclude that the population mean is lower than the moderate score of 4.0? Explain. c. Would the confidence interval be wider, or narrower, (i) if you constructed a 99% confidence interval and (ii) if n le 8.46 Sim for a TRY Sele TECH skew the 30 a =500 instead of 1874? click 8.41 Length of hospital stays A hospital administrator wants to estimate the mean length of stay for all inpatients using that hospital. Using a random sample of 100 records of pa- tients for the previous year, she reports that "The sample mean was 5.3 days. In repeated random samples of this size, the sample mean could be expected to fall within one day of the true mean about 95% of the time." Explain the meaning of this sentence from the report, showing what it suggests about the 95% confidence interval. 8.42 Effect of n Find the margin of error for a 95% confi- dence interval for estimating the population mean when con from a. t b. H c. N V