SOLUTION: The random variable X is normally distributed with mean 79 and variance 144. Find P(X<70) P(64< X <96)

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Question 384105: The random variable X is normally distributed with mean 79 and variance 144.
Find
P(X<70)
P(64< X <96)

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Find the z score,
z=%28x-mu%29%2Fsigma
z=%28x-mu%29%2Fsqrt%28VAR%29
z=%2870-79%29%2Fsqrt%28144%29=-9%2F12=-0.75
Now find P%28x%3C70%29=P%28z=-0.75%29
That's your solution.
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Find two z scores,
z%5B1%5D=%2864-79%29%2Fsqrt%28144%29
z%5B2%5D=%2896-79%29%2Fsqrt%28144%29
and
P%2864%3C+x+%3C96%29=P%28z%5B2%5D%29-P%28z%5B1%5D%29