SOLUTION: Scores on a test have a mean of 63 and Q3 is 82. The scores have a distribution that is approximately normal. Find the standard deviation. Round your answer to the nearest tenth
Algebra ->
Probability-and-statistics
-> SOLUTION: Scores on a test have a mean of 63 and Q3 is 82. The scores have a distribution that is approximately normal. Find the standard deviation. Round your answer to the nearest tenth
Log On
Question 581209: Scores on a test have a mean of 63 and Q3 is 82. The scores have a distribution that is approximately normal. Find the standard deviation. Round your answer to the nearest tenth. Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Scores on a test have a mean of 63 and Q3 is 82. The scores have a distribution that is approximately normal. Find the standard deviation. Round your answer to the nearest tenth.
----
Q3 has a left-tail of 0.75
---
Find the corresponding z-score:
invNorm(0.75) = 0.6745
----
Equation:
Use x = zs+u to find "s":
82 = 0.6745*s+63
0.6745s = 19
s = 19/0.6745
s = 28.1694
==================
Cheers,
Stan H.
(