SOLUTION: Assume that men have IQ scores that are normally distributed with a mean of 99 and a standard deviation of 13. Find the IQ score that separated the lower 30% of the others. Round u

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Question 1069505: Assume that men have IQ scores that are normally distributed with a mean of 99 and a standard deviation of 13. Find the IQ score that separated the lower 30% of the others. Round up to the nearest integer.
a) 92
b) 93
c) 94
d) 95
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Find the z score so that P%28Z%29=0.3
P%28Z%29=0.3
Z=-0.5244
%28X-99%29%2F13=-0.5244
X-99=-6.817
X=92.2
X=92
I rounded down because the decimal portion was less than 5 (as is done for standard rounding up instruction).
Your instructions said to round up so the solution may be X=93 if we follow your strict instructions.