A study of college football games shows that the number of holding

A study of college football games shows that the number of holding penalties assessed has a mean of 2.2 penalties per game and a standard deviation of 1.1 penalties per game. What is the probability that, for a sample of 40 college games to be played next week, the mean number of holding penalties will be 2 penalties per game or less 

To determine the possible effect of a chemical treatment on the rate of seed germination, 350 chemically treated seeds and 200 untreated seeds were sown. It was found that 315 of the chemically treated seeds and 172 of the untreated seeds germinated. Let p1 be the proportion of the population of all chemically treated seeds that germinate, and let p2 be the proportion of the population of all untreated seeds that germinate. Find a 90% confidence interval for p1-p2.