A survey of a random sample of 40 actuarial scientists who passed all their exams and are 7. working in the field of actuarial sciences found the sample average salary to he $125,000 and the standard...

Extracted text: A survey of a random sample of 40 actuarial scientists who passed all their exams and are 7. working in the field of actuarial sciences found the sample average salary to he $125,000 and the standard deviation to be $15,000. A. Find the 90% confidence interval for the true average salary of actuarial scientists. B. If it is desired to be 95% confident that the sample mean is within $4,000 of the true average salary of actuarial scientists, how many actuarial scientists should the survey have?