SOLUTION: Two students take a college entrance exam known to have a normal distribution of scores. The students receive raw scores of 63 and 93, which correspond to z scores (often called th

Algebra ->  Probability-and-statistics -> SOLUTION: Two students take a college entrance exam known to have a normal distribution of scores. The students receive raw scores of 63 and 93, which correspond to z scores (often called th      Log On


   

Question 353733: Two students take a college entrance exam known to have a normal distribution of scores. The students receive raw scores of 63 and 93, which correspond to z scores (often called the standardized scores) of –1 and 1.5, respectively. Find the mean and standard deviation of the distribution of raw exam scores.
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
z=%28x-mu%29%2Fsigma
-1=%2863-mu%29%2Fsigma
1.5=%2893-mu%29%2Fsigma
.
.
1.-sigma%2Bmu=63
2.1.5%2Asigma%2Bmu=93
Subtract eq. 1 from eq. 2,
1.5%2Asigma%2Bmu%2Bsigma-mu=93-63
2.5%2Asigma=30
highlight%28sigma=12%29
Then use either equation to solve for mu.
-12%2Bmu=63
highlight%28mu=75%29