# A set of test scores is normally distributed with a mean of 78 and a standard deviation of 4.5. Dwayne scored 87 on the test. What is his percentile score?

##### 1 Answer

Jun 11, 2017

#### Explanation:

The question requires z-scores.

The formula is:

Where

Or

This is a bit easier to remember :)

(SD=Standard Deviation)

Plug in the values:

Now you look up the probability that corresponds to the

The probability that corresponds to the

All you have to do now is multiply by