Posted by CYNTHIA on Friday, March 29, 2013 at 11:25am.
3. Sickleave 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.

statistics3.  MathGuru, Monday, April 1, 2013 at 7:47pm
Formula with your data included:
CI90 = 25.6 + or  1.645(5.1/√200)
Calculate for your interval.