A test is scaled so that the mean score is 490 and the standard deviation is 100. What percentage of students taking this test should score 720 or​ more? Assume a normal distribution.

Question

Finite Math Problem

A test is scaled so that the mean score is

490 and the standard deviation is 100. What percentage of students taking this test should score 720 or​ more? Assume a normal distribution.

Answer 1

If you have a TI-84 calculator, use "normalcdf" which is found under the "distr" button functions.

Select 720 as the "lower"

Select a really big number (such as 1000000) for the "upper"

Select 490 as the mean and select 100 as the standard deviation

Select "Paste" and hit "enter" then hit "enter" again.

The answer is 0.010724 or 1.07%