Question

The scores on a test are normally distributed with a mean of 80 and a standard deviation of 16. What is the score that is 2 1/2 standard deviations above the mean? A score of _ is 2 1/2 standard deviations above the mean.

Answer 1

Given:

The scores on a test are normally distributed.

The mean = μ = 80

The standard deviation = σ = 16

we will find the score that is 2 1/2 standard deviations above the mean

Le the score = x, so, z = 2 1/2

We will use the following formula to find x

$x=\mu\pm z\sigma$

substitute the given values

$x=80+2.5*16=120$

So, the answer will be:

A score of 120 is 2 1/2 standard deviations above the mean.