Please solve asap my deadline is close.

The weekly number of Jazz records sold has been observed in 20 music shops of a certain chain and it yielded that the observed data have a sample mean :3 = 160 and a sample standard deviation equal to 46. An analogous study has been done for another chain in its 12 shops. it has been observed a sample mean r = 90 and a sample standard deviation equal to 35. Suppose the hypothesis of normality of the data. I. Give a 90% condence interval for the mean pg of the (weekly) number of Jazz records sold by a shop of the rst chain. 2. Consider the test Ha : px = pr versus H; : px g py with condence level 95%. Which kind of assumption do you further need to suppose? 3. Consider the test Ho 1 of," = or)\"; versus H1 : a} 96 of... 'thh a signicance level of a = 0.05. can you reject the hypothesis that the two populations have the same variance