MATH
posted by Lee Ann .
Suppose that people's heights (in centimeters) are normally distributed, with a mean of 175 and a standard deviation of 6. We find the heights of 80 people.
(a) How many would you expect to be between 168 and 182 cm tall?
(b) How many would you expect to be taller than 170 cm?

http://davidmlane.com/hyperstat/z_table.html This is an excellent distribution applet.
Enter the mean, and standard deviation
a) enter between numbers, note the shaded area, and the computation .7566 at the bottom. That means 80*.7566 =60.52 number , which means 60 people between (some add the .52, but it is hard to count .52 folks).