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Chapter 7: Q. 1.1 (page 448)

The length of human pregnancies from conception to birth varies according to a distribution that is approximately Normal with mean 266days and standard deviation 16days.

1. Find the probability that a randomly chosen pregnant woman has a pregnancy that lasts for more than 270days. Show your work.

Suppose we choose anSRSof 6 pregnant women. x炉=the mean pregnancy length for the sample.

Short Answer

Expert verified

The probability is 0.4013 .

Step by step solution

01

Given Information

Population mean (渭)=266

Population standard deviation (蟽)=16

02

Explanation

The probability that a randomly selected woman has a pregnancy that would be above270days can be calculated as:

localid="1650103880143" P(X>270)=Px-渭蟽>270-渭蟽=PZ>270-26616=P(Z>0.25)=0.4013

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