A college admissions director wishes to estimate the mean age of all students currently enrolled. In a random sample of 15students, the mean age is found to be 23years. From past studies, the ages of enrolled students are normally distributed with a standard deviation of 10.3years. Construct a 90% confidence interval for the mean age of all students currently enrolled.

1. The critical value:

2. The standard deviation of the sample mean:

3; The margin of Error

4. The lower limit of the interval:

5. The upper limit of the interval: