Question

The last math exam of the year was normally distributed with a mean of 85 and a standard deviation of 5. Xavier needed at least a 95 on this test to get an A for the year. His teacher gave him his z-score: 1.8. Did Xavier get an A for the year?

Answer 1

Xavier did not get an A for the year.

Explanation:

We solve this question using z score formula

= z = (x-μ)/σ, where

x is the raw score = ?

μ is the population mean = 85

σ is the population standard deviation = 5

z = 1.8

Hence

1.8 = x - 85/5

Cross Multiply

1.8 × 5 = x - .5

9 = x - 85

Collect like terms

9 + 85 = x

x = 94

Xavier scored 94.

He needs at least 95 to get an A.

Therefore, we can conclude that Xavier did not get an A for the year.