Question 1032356
The lengths of pregnancies in a small rural village are Normally distributed with a mean of 263 days and a standard deviation of 14 days. 
What percentage of pregnancies last fewer than 252 days? 
P(X < 252) 
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z(252) = (252-263)/14 = -11/14
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P(x < 252) = P(z < -11/14) = normalcdf(-100,-11/14) = 0.2160
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Cheers,
Stan H.
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