Question

A philosophy professor assigned letter grades on its test according to the following schemeScores on the test are normally distributed with a mean of 81.2 and a standard deviation of 8.1Find the minimum score required for an A grade round your answer to the nearest whole number if necessary

Answer 1

Given;

`\mu=81.2,\sigma=8.1,P(A)=0.12`

The z-score of the probability is 1.175.

Thus, using the z-score formula;

`\begin{gathered} z=(x-\mu)/(\sigma) \\ \\ 1.175=(x-81.2)/(8.1) \\ \\ x\approx91 \end{gathered}`

The minimum score