Question 309463: There are 8,000 students at the university of Tennessee at Chattanooga. The average age of all the students is 24 years with a standard deviation of 9 years. A random sample of 36 students is selected.
a. determine the standard error of the mean.
b. what is the probability that the sample mean will be larger than 19.5?
c, what us the probability that the sample mean will be between 25.5 and 27 years?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! There are 8,000 students at the university of Tennessee at Chattanooga. The average age of all the students is 24 years with a standard deviation of 9 years. A random sample of 36 students is selected.
a. determine the standard error of the mean.
Ans: s = 9/sqrt(36) = 3/2
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b. what is the probability that the sample mean will be larger than 19.5?
z(19.5) = (19.5-24)/(3/2) = -3
P(x-bar < 19.5) = P(z < -3) = normalcdf(-100,-3) = 0.0013
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c, what us the probability that the sample mean will be between 25.5 and 27 years?
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z(27) = (27-24)/(3/2) = 2
z(25.5) = (25.5-24)/(3/2) = 1
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P(15.5< x < 27) = P(1< z < 2) = normalcdf(1,2) = 0.1359
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Cheers,
Stan H.
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