SOLUTION: Please help. I have tried to find similar problems and work this out but I have only confused myself more. Thank you, it is the only one I haven't been able to answer and it is d
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Question 720784: Please help. I have tried to find similar problems and work this out but I have only confused myself more. Thank you, it is the only one I haven't been able to answer and it is due 3/2/13.
Assume that the population of heights of male college students is approximately normally distributed with mean u of 69.66 inches and standard deviation o of 6.08 inches. A random sample of 84 heights is obtained. Show all work.
(A) Find P(x>68.75)
(B) Find the mean and standard error of the x-bar distribution
(C) Find P(x-bar>68.75)
(D) Why is the formula required to solve (A) different than (C)?
You can put this solution on YOUR website! Assume that the population of heights of male college students is approximately normally distributed with mean u of 69.66 inches and standard deviation o of 6.08 inches. A random sample of 84 heights is obtained. Show all work.
(A) Find P(x > 68.75)
z(68.75) = (68.75-69.66)/6.08] = -0.1497
P(x > 68.75) = P(z > -0.1497) = normalcdf(-0.1497,100) = 0.5595
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(B) Find the mean and standard error of the x-bar distribution
mean = 69.66 ; std = 6.08/sqrt(84) = 0.6634
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(C) Find P(x-bar>68.75)
P(x-bar > 68.75)
z(68.75) = (68.75-69.66)/[6.08/sqrt(84)] = -1.3718
P(x-bar) > 68.75) = P(z > -1.3718) = normalcdf(-1.3718,100) = 0.9149
(D) Why is the formula required to solve (A) different than (C)?
The Central Limit Theorem explains that.
Cheers,
Stan H.
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