Discussion:
Q1. Dunkin Donuts advertises that a dozen of their donuts weighs about 43 oz. A certain baker has figured out that she can stay out of trouble with her manager if each donut weighs about 3.6 oz. To test her donut-making process, she randomly selects thirty-one donuts after baking and weighs them. The average of the sample is 3.504 oz with s = 0.109 oz. Construct a 95% confidence interval for the true population mean of donut weights, and then explain whether or not she will be in trouble.
Q2. Scores for men (nationwide) on the verbal portion of the SAT test are normally distributed with a mean of 509 and a standard deviation of 112. Randomly selected men are given the Columbia review course before taking the SAT test. After the course, a sample of 49 men revealed an average of 535 points and a standard deviation of 90 points. Using a significance level of 0.05, test the claim that the review course students have a mean score greater than or equal to the normal population. (use the 5-step method).