deviation s. 16. A sample consists of 75 TV sets purchased several years ago. The replacement times of those TV sets have a mean of 8.2 years and a standard deviation of 1.1 years (based on data from "Getting Things Fixed," Consumer Reports). Construct a 90% confidence interval for the standard deviation of replace- ment times for all TV sets from that era. Does the result apply to TV sets cur- rently being sold?study suggests that o = 21.2. 18. To plan for the proper handling of household garbage, the city of Fredericton must estimate the mean weight of garbage discarded by house- holds in one week. Find the sample size necessary to estimate that mean if you want to be 96% confident that the sample mean is within 2 1b of the true population mean. For the population standard deviation s, use the value of 12.46 1b, which is the standard deviation of the sample of 62 households included in Data Set 1