determining probability

#1
Hi
I'm stumped with a probability question for my course.

The data collected from the 20 sampled students as stated in question 1 is as follows:

5
5
3
4
5
8
4
6
8
4
5
3
3
7
6
7
5
5
6
8


1.1The average number of hours worked by the selected students is normally distributed with a mean of 5 and a standard deviation of 2 hours. The question is to determin the probability of how many students work more than 8 hours per day.

im stumped. do i need to refer to a probability table?

i
 
#2
Yes. Here's a start. Draw a normal curve, and put a scale of hours on the bottom. Put a matching scale with z values. Shade in the area you are interested in. Find out how to convert hours to z's. find out how to convert z's to areas.