Question 1186844
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The length of a human pregnancy is normally distributed with a mean of 272 days with a standard deviation 
of 9 days (Bhat & Kushtagi, 2006). How many days would a pregnancy last for the shortest 20%? Round answer to 2 decimal places. 
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<pre>
You are given a normal curve with the mean value of 272 days and the standard deviation of 9 days.


They want you find a raw mark t (days) such that 20%, or 0.2 of the area under the normal curve

be on the left of the mark t.


Use a standard function invNorm in your calculator TI-83/84

                area  mean  SD    <<<---===  formatting pattern
    t = invNorm(0.2,  272,   9)


and get the <U>ANSWER</U>  t = 264.43  days.
</pre>

Solved.