statistics
posted by Michelle on .
the average number of years a person takes to complete a graduate degree program is 3. the standard deviation is 4 months. Assume the variable is normally distributed. If an individual enrolls in the program, find the probability that it will take.
a) More than 4 years to complete the program
b) Less than 3 years to complete the program
c) Between 3.8 and 4.5 years to complete the program
d) Between 2.5 and 3.1 years to complete the program

mean= 36months standard deviation=4
Use this applet; http://davidmlane.com/hyperstat/z_table.html