Question

The average score on a standardized test is 750 points with a standard deviation of 50 points. If 2,000
students take the test at a local school, how many students do you expect to score between 700 and 750
points?

Answer 1

First get the variance from the std dev. Then multiply variance as well as scores by 2000. Then convert the new variance back to a std dev. Than just fill in these values in the NormalCDF function of your calculator to get the probability, then multiply the probability by the amount of student who took the test.

Answer 2

http://m.wolframalpha.com/input/?i=normalcdf%281400000%2C1500000%2C1500000%2C2236%29&x=-988&y=-71