Annie was told that her math test score was 3 standard deviations below the mean. If test scores were approximately normal with μ=99 and σ=4, what was Annie's score? Do not include units in your answer. For example, if you found that the score was 99 points, you would enter 99.

Where and

We want to find the Annie's score takign in count that the score is 3 deviations below the mean, so then we can find the value with this formula:

And replacing we got:

So then the Annie's score would be 87

Step-by-step explanation:

Let X the random variable that represent the test scores of a population, and for this case we know the distribution for X is given by:

Where and

We want to find the Annie's score takign in count that the score is 3 deviations below the mean, so then we can find the value with this formula:

And replacing we got:

So then the Annie's score would be 87

you already gave the answer

step-by-step explanation: