Question

Age at childbirth. In the last decade, the average age of a mother at childbirth is 26.4 years, with standard deviation 5.8 years. The distribution of age at childbirth is approximately normal. (a) What proportion of women who give birth are 21 years of age or older? (b) Giving birth at what age puts a woman in the upper 2.5% of the age distribution?

Answer #1

a)

82.4 1%

b) p(Z>1.96) = 0.025

corresponding z score is 1.96,it means above 1.96 area under standard normal distribution curve is 2.5 %

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