SOLUTION: Hi... I'm stuck, and don't know where to begin. The length of human pregnancies varies normally with a mean of 266 days and a standard deviation of 16 days. What percentage o

Algebra ->  Probability-and-statistics -> SOLUTION: Hi... I'm stuck, and don't know where to begin. The length of human pregnancies varies normally with a mean of 266 days and a standard deviation of 16 days. What percentage o      Log On


   

Question 1081375: Hi... I'm stuck, and don't know where to begin.
The length of human pregnancies varies normally with a mean of 266 days and a standard deviation of 16 days.
What percentage of pregnancies last longer than 282 days?
16%
5%
68%
32%
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Calculate a z score and then calculate the probability from the z score,
z=%28X-mu%29%2Fsigma
z=%28282-266%29%2F16=1
Find P%28z=1%29, then the percentage of pregnancies longer would be,
P=1-P%28z=1%29