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

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.
RELATED QUESTIONS
Scores on a test have a mean of 71 and Q3 is 82. The scores have a distribution that is... (answered by rothauserc)

Scores on a test have a mean of 73 and Q3 is 83. The scores have a distribution that is... (answered by Theo)

Scores on a test have a mean of 73 and 10 percent of the scores are above 87. The scores... (answered by oscargut)

ACT scores have a mean of 21.3 and 8 percent of the scores are above 27. The scores have... (answered by CPhill)

scores from a test have a mean of 64.6. the distribution sample means for size 100 is... (answered by stanbon)

Please help me solve this problem, based on the examples in the book, I can't figure it... (answered by stanbon)

Two students take a college entrance exam known to have a normal distribution of scores.... (answered by Fombitz)

Please help me to solve this two students take a college entrance exam known to have a... (answered by Solver92311)

in a certain population, the mean score on a test is 105. If the distribution of scores... (answered by stanbon)