A dollar store wants to estimate the mean retail value of goods that it has in its inventory. A random sample of 100 goods indicates a mean value of $2.55 and a standard deviation of $0.44. Assuming a normal distribution, construct the 90% confidence interval estimates for the mean value of all goods in the store's inventory. 90% (4 d.p. ): lower limit = upper limit = If we construct a 95% confidence interval, will the interval be wider or narrower than the 80% one? (copy-paste wider or narrower) The store conducts a customer satisfaction survey on 1,000 individuals. In response to the question of are you satisfied with the service, 68% said yes, 19% said somewhat, and 7% said no. Construct a 95% confidence interval estimate of the population proportion of customers who are somewhat satisfied. (4 d.p.) lower limit = upper limit = You have been asked to reconduct the survey. Determine the sample size necessary to estimate, with 95% confidence, the population proportion of somewhat satisfied to within plus/minus 0.02. sample size =