SOLUTION: Assume that the population proportion of adults having a college degree is 0.48. A random sample of 250 adults is to be selected to test this claim.
A) What are the shape, mean,
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A) What are the shape, mean,
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Question 1099382: Assume that the population proportion of adults having a college degree is 0.48. A random sample of 250 adults is to be selected to test this claim.
A) What are the shape, mean, and standard deviation of the sampling distribution of the sample proportion for samples of 250?
B) What is the probability that the sample proportion will be less than 0.54?
C) What is the probability that the sample proportion will fall within 4 percentage points(+/- 0.04) of the population proportion? Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! the mean is 120, since that is 0.48 of 250
The variance is 120*0.52 np(1-p)=62.4
the sd is sqrt (62.4)=7.9
less than 0.54 is a number of 135
use 134.5
(134.5-120)/7.9 is the z value below which we are interested
that would be z < 14.5/7.9=+1.84
or 0.9671
Within 0.04 is within 10 people
this is within 110 and 130, including
(109.5-120)/7.9 is z of -1.33
(130.5-120)/7.9 is z of +1.33
That probability is 0.8165.