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Show all your work. Suppose the energy need during pregnancy is normally distrib

ID: 3254812 • Letter: S

Question

Show all your work. Suppose the energy need during pregnancy is normally distributed with a mean mu = 2500 kcal/day and standard deviation sigma = 50 kcal/day. (a) What is the probability that a randomly selected pregnant woman has an energy need of more than 2525 kcal/day? (b) Describe the sampling distribution of x, the sample mean daily energy requirement for a random sample of 25 pregnant woman (c) What is the probability that a sample of 25 pregnant women has a mean energy of more than 2525 kcal/day?

Explanation / Answer

Answer:

a).

z value for 2525, z =(2525-2500)/50 =0.5

P( x >2525) = P( z >0.5)

=0.3085

b).

sampling distribution of mean x is normal distribution with

mean =2500

standard error = sd/sqrt(n) = 50/sqrt(25) =10

c).

z value for 2525, z =(2525-2500)/10 =2.5

P( mean x >2525) = P( z >2.5)

=0.0062