SOLUTION: The scores on a certain test are normally distributed with a mean score of 43 and a standard deviation of 3. What is the probability that a sample of 90 students will have a mean

Algebra ->  Probability-and-statistics -> SOLUTION: The scores on a certain test are normally distributed with a mean score of 43 and a standard deviation of 3. What is the probability that a sample of 90 students will have a mean      Log On


   

Question 449735: The scores on a certain test are normally distributed with a mean score of 43 and a
standard deviation of 3. What is the probability that a sample of 90 students will have a
mean score of at least 43.3162?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The scores on a certain test are normally distributed with a mean score of 43 and a standard deviation of 3. What is the probability that a sample of 90 students will have a mean score of at least 43.3162?
---------------------------------
t(43.3162) = (43.3162-43)/[3/sqrt(90)]
---
= (0.3162)/[0.3162] = 1
============================
P(x-bar >= 43.3162) = P(t > 1 when df = 89) = 0.1600
=====================
Cheers,
Stan H.
=====================