I can't figure out these problems...

#1
I have been trying to figure out these problems all week and the assignment is due tomorrow! I went to the on campus tutoring center and they couldn't explain it in a way that I understand and my professor barely speaks english!!!! HELP!!!!

The problems are as follows:

A. If the average time a health club member spends exercising is 80 minutes with a standard deviation of 16 minutes and assuming the data are normally distributed, then

1. what percentage of health club members exercise between 60 minutes and 90 minutes. (in percentage and two decimal)

2. what percentage of health club members exercise more than 120 minutes?

B. if the average time to finish an IQ test is 90 mins with a standard deviation of 15 minutes and assuming the data is normally distributed then:

3. what percentage of test takers finish in more than 105 minutes?

4. what percentage finish in less than 72 minutes?

5. find the time that separates the fastest 10% who finish the test?
 
#2
Bummer. Hope this worked out for you, I can see the post is pretty old. If you still need help though, I'd be happy to explain this to you.


Rich