1. A random sample of 10 weeks of hospitals in Pennsylvania has a mean number of infections per week of 17.7 infections, and a sample standard deviation is 1.8. Construct a 95% condence interval for the population mean u of the average number of infections in all hospitals in Pennsylvania. 2. In a survey of 2230 US adults, 57% think that air travel is much more reliable than taking cruises. Find the margin of error in estimating, with 96% condence, the population proportion of US adults who think that air travel is much more reliable than taking cruISes. 3. In each case, nd the minimum sample size required to estimate the population proportion p with 92% condence, if you want to x the error as 0.06 a) Assume that is near 0.3 b) Assume that you have no prior knowledge about , but you wish to be certain that your sample is large enough to achieve the specied accuracy for the estimate. 4. A sample of 32 adult elephants had an average weight of 12,300 pounds. The standard deviation for the sample was 22 pounds. Find a 99% condent interval of the population mean for the weight of adults elephants