Solve and explain

Question 11 Scores on Math 227 Statistics exam one has a mean of 75 and a standard deviation of 7. Assume the scores distribution is normal. Suppose that 12 randomly selected a students. Answer the following questions. Round all answers to 4 decimal places where possible. a. What is the distribution of X? X - N b. What is the distribution of a? a - N c. To receive a B on the test, it is required to score between 80 and 90. What is the probability of students earned a B? d. For the group of 12 students, find the probability that they score a B , that is, they score between 80 and 90. e. For part d), is the assumption of normal necessary? (Yes No