5. Shopper Purchases A shopper in a grocery store pur- chases 22 items on average. A store manager believes that the mean is greater than 22. She surveyed a random- ly selected group of 36 customers and found that the mean of the number of items purchased was 23.2. The population standard deviation is 3.7 items. At a = 0.05, can it be concluded that the mean is greater than 22 items