Question

Addison earned a score of 510 on Exam A that had a mean of 550 and a standarddeviation of 40. She is about to take Exam B that has a mean of 26 and a standarddeviation of 5. How well must Addison score on Exam B in order to do equivalentlywell as she did on Exam A? Assume that scores on each exam are normallydistributed

Answer 1

Exam A:

$\begin{gathered} \text{Score (x)=510} \\ \mu\text{ (mean)=55}0 \\ \sigma\text{ (standard deviation)=40} \end{gathered}$

$\begin{gathered} Z\text{ = }\frac{x\text{ -}\mu}{\sigma} \\ Z\text{ = }\frac{510-550}{40}=-1 \end{gathered}$

Z = -1, then...

Exam B:

$\begin{gathered} x\text{ = ?} \\ \mu=26 \\ \sigma=5 \end{gathered}$$x=Z\times\sigma+\mu=-1\times5+26=21.00$

Answer: 21