SOLUTION: A distribution of values is normal with a mean of 70 and a standard deviation of 25. From this distribution, you are drawing samples of size 32. Find the interval containing the

Algebra ->  Probability-and-statistics -> SOLUTION: A distribution of values is normal with a mean of 70 and a standard deviation of 25. From this distribution, you are drawing samples of size 32. Find the interval containing the      Log On


   



Question 1180821: A distribution of values is normal with a mean of 70 and a standard deviation of 25. From this distribution, you are drawing samples of size 32.
Find the interval containing the middle-most 66% of sample means:

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
z for (17%) is -0.94, for 83% it is +0.954
So the middle 66% is between those two z values
z=(x-mean)/sd
-0.954=(x-70)/25/sqrt(32)
-0.954=(x-70)/4.419
x-70=-4.216, round to -4.22
x=65.78 and for the upper limit, 74.22
(65.78, 74.22)