Question

james works an average of 22 hours per week with a standard deviation of 3.5 hours. what percentage of the time does james work more than 31 hours per week?

Answer 1

(31-22)/3.5 = 2.57

so look up Z>2.57 in your handy dandy Z table.

Answer 2

on davidmlane's page,

http://davidmlane.com/hyperstat/z_table.html

enter: mean = 22 , sd = 3.5
click on "above" and enter 31 to get

.0051