SOLUTION: Good afternoon everyone, if anyone who can help me out would be greatly appreciated thank you in advance and enjoy the rest of your day!!! 3)The GPA of all students at a large u

Algebra ->  Probability-and-statistics -> SOLUTION: Good afternoon everyone, if anyone who can help me out would be greatly appreciated thank you in advance and enjoy the rest of your day!!! 3)The GPA of all students at a large u      Log On


   



Question 870773: Good afternoon everyone, if anyone who can help me out would be greatly appreciated thank you in advance and enjoy the rest of your day!!!
3)The GPA of all students at a large university has an approximate normal distribution with a mean of 3.02 and a standard deviation of .29. Find the probability that the mean GPA of a random sample of 20 students selected from the university is:
a) 3.10 or higher
b) 2.90 or lower
c) Find P90 and P50 for the GPA

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
Sample of 20: .29/sqrt(20) = .0648
a) z = .08/.0648
b) z = -12/.0648 = -1.8519, P(z < -1.8519) = 3.20%
c) P90,
1.28 = (X - 3.02)/.0648 = 3.102304