# A market research company employs a large number of typists to enter data into a computer. The time it takes for new typists to learn the computer system is known to have a normal distribution with a mean of 90 minutes and a standard deviation of 18 minutes. What is the proportion of new typists who take more than two hours to learn the computer system?

##### 1 Answer

Feb 26, 2015

Below is the way you do this on a **TI-83 plus** or similar

Go to the

**NormalCdf** works with the following parameters:

*very* large number)

So you fill in: