Question

eli earned a score of 390 on exam a that had a mean of 300 and a standard deviation of 40. he is about to take exam b that has a mean of 600 and a standard deviation of 100. how well must eli score on exam b in order to do equivalently well as he did on exam a? assume that scores on each exam are normally distributed.

Answer 1

score = 825

Explanation:

we first need to find z-score for exam A:

z = (x - υ) / σ

where x is observed value, υ is the mean and σ is the standard deviation.

For A:

z = (x - υ) / σ

= (390 - 300) / 40 = 2.25.

we need him to get z-score of 2.25 on exam B. his score is x.

2.25 = (x - 600) / 100

225 = x - 600

x = 825.

so he needs to score 825 on exam B to do equivalently well as on exam A.