Question 4 At a particular university, students' grades in introductory statistic classes are generally unimodal and skewed to the left with a Question 6 Andy is a product manufacturer. He believes 75% of his customers are satisfied with the quality of his products. From a random Tries mean of u = 66% and a standard deviation of o = 15.0%. (Round your answers to 4 decimal places, if needed.) sample of 91 customers, what are the following probabilities? (If necessary, use the sampling distribution of the sample proportion, remaining: 1 Tries remaining: 1 NOT the normal approximation to binomial.) Marked out of (a) The distribution of students' grades is approximately normal 9.00 Marked out of Flag 3.00 (a) What is the probability that less than 69 customers are satisfied with the quality? (Round your answers to 4 decimal places, if question (b) If n = 33 students are selected at random, the distribution of the sample mean grade is approximately normal + with a Flag needed.) mean of and a standard deviation of question (b) What is the probability that at least 69 customers are satisfied with the quality? (Round your answers to 4 decimal places, if (c) The probability that the sample mean grade for these 33 students is less than 72% is needed.) (d) If n = 33 students are selected at random, the distribution of the sample total grade is approximately normal * with a mean (c) What is the probability that the sample proportion of customers who are satisfied with the quality is between 72% and 80%? of and a standard deviation of (Round your answers to 4 decimal places, if needed.) (e) The probability that the total grade for these 33 students is less than 2376 is Check Check