The mean (μ) of the scale is 98 and the standard deviation (σ) is 13. Assuming that the scores are normally distributed, what is the PROBABILITY that a score falls below 88?

Answer 1

Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the Z score.

Answer 2

What is the approximate probability that x will differ from μ by more than 0.8?