solution National Cookie Company revisited (see Problem 11 on Problem Set 3). Suppose that National is concerned that the process by which the mean weight level is adjusted is not working accurately. To investigate this, National decides to set the mean weight at 25.6 grams and then take a sample of 150 cookies from the output of the production process. National is still willing to assume that the standard deviation is 0.6 grams per cookie. Each of the 150 cookies in the sample is weighed on a very precise scale, and the average weight for the 150 cookies is 25.2 grams. Based on this data, find a 95% interval for the mean weight level. What do you think about the accuracy of the adjustment of the mean weight level
