I'm having trouble with part B. The mean is 3.24 and the standard deviation is 0.19.

The undergraduate grade point averages (UGPA) of students taking an admissions test in a recent year can be approximated by (a) What is the minimum UGPA that would still place a student in the top 5% of UGPAs? (b) Between what two values does the middle 50% of the UGPAs lie? (a) The minimum UGPA that would still place a student in the top 5% of UGPAs is 3.55. (Round to two decimal places as needed.) (b) The middle 50% of UGPAs lies between 1.96 on the low end and 3.61 on the high end. (Round to two decimal places as needed.)