3. Sick-leave records obtained from a random sample of 200 social workers showed a mean number of days sick leave equal to 25.6 last year. If the sample standard deviation is 5.1, construct a 90% confidence interval for the mean number of days sick leave for all social workers last year.

Answer 1

Formula with your data included:

CI90 = 25.6 + or - 1.645(5.1/√200)

Calculate for your interval.