Question

Scores on a recent exam followed a normal distribution and letter grades will be assigned with 15% A, 35% B, 30% C, 15% D, and 5% F. Suppose that Sue took the exam and had a standardized score of 0.85. What letter grade will Sue get?

Answer 1

Using the normal distribution, it is found that Sue will get a letter grade of B.

In a normal distribution with mean $\mu$ and standard deviation $\sigma$, the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

• It measures how many standard deviations the measure is from the mean.  
• After finding the z-score, we look at the z-score table and find the p-value associated with this z-score, which is the percentile of X.

In this problem, Sue got a grade of 0.85, hence $z = 0.85$.

• Looking at the z-table, z = 0.85 has a p-value of 0.8023, hence she is approximately in the top 20%, which is below the top 15% but above the top 50%, hence she got a letter grade of B.

A similar problem is given at brainly.com/question/25745464