Question

The scores on a recent test are normally distributed, Sally's score of 63 was 2 standard deviations below the mean and Jamal's score of 95 was 3 standard deviations above the mean. What are the mean and standard deviation for the test?

Answer 1

A.mean:79;SD 2 B. mean:75.8;SD:6.4 C. mean:32;SD7.2 D. mean: 79.5:SD 6.1

Answer 2

From the given info you have the following system of equations,
\[\begin{cases}
63=\mu-2\sigma\\
95=\mu+3\sigma
\end{cases}\]
Solve for \(\mu\) and \(\sigma\), which denote the mean and standard deviation, respectively.