Professor is told that the grades on a standardized statistics test are normally distributed with a mean of 78 and a standard deviation of 5.

If Prof. were to take a random sample of 25 tests and the compute the average,

then what is the probability that the average of these tests is greater than 80.5?

a.none of these

b.0.62%

c.2.5%

d.1.24%

e.49.38%