Suppose a random sample of 25 students is selected from a community college where the scores in the final exam (out of 125 points) are normally distributed, with mean equal to 112 and standard deviation equal to 12. Find the probability that the sample mean deviates from the population mean ì = 112 by no more than 4.

Question

Suppose a random sample of 25 students is selected from a community college where the scores in the final exam (out of 125 points) are normally distributed, with mean equal to 112 and standard deviation equal to 12. Find the probability that the sample mean deviates from the population mean ì = 112 by no more than 4.
a.0.9050
b.0.9554
c.0.8767
d.0.9914

PsyDAG · Answer

I don't see how it could be normally distributed with max of 125, mean = 112 and SD = 12. There could be no scores above 125, which is slightly more than 1 SD above the mean.