The gestation time for humans has a mean of 266 days and a standard deviation of...

The gestation time for humans has a mean of 266 days and a standard deviation of 20 days. If 100 women are randomly selected, find the probability that they have a mean pregnancy between 266 days and 268 days.

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Expert Solution

Solution :

Given that,

mean = = 266

standard deviation = =20

n = 100

= 266

₌ / $\sqrt$ n = 20 $\sqrt$ 100 = 2

P (266 < < 268)

P ( 266 - 266 / 2) < ( - / ) < ( 268 - 266 / 2)

P ( 0 / 27 < z < 2 / 2)

P ( 0 < z < 1 )

P ( z < 1 ) - P ( z < 0 )

Using z table

- 0.8413 - 0.5000

= 0.3413

Probability = 0.3413

orchestra answered 1 year ago

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