SOLUTION: The mean and standard deviation of exam score are 49% and 9% respectively.Assuming that examintion are normally distributed,calculate the probability of score: A.less than 50% B.

Algebra ->  Probability-and-statistics -> SOLUTION: The mean and standard deviation of exam score are 49% and 9% respectively.Assuming that examintion are normally distributed,calculate the probability of score: A.less than 50% B.      Log On


   

Question 1021892: The mean and standard deviation of exam score are 49% and 9% respectively.Assuming that examintion are normally distributed,calculate the probability of score:
A.less than 50%
B.more than 45%
C.between 52% and 63%
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Use the z score,
A.z=%28x-mu%29%2Fsigma=%2850-49%29%2F9=0.1111
P%28z%29=0.5442
B.z=-0.4444
P=1-P%28z%29=1-0.3284=0.6716
C.z%5B1%5D=%2852-50%29%2F9=0.3333
z%5B2%5D=1.5556
P=P%282%29-P%281%29=0.9401-+0.6306=0.3095