SOLUTION: a sample of the reading scores of 29 fifth gtaders has a mean of x(with the bar on top of the x)=83 and a population standard deviation of r=10.5.
a. Find 99% confidence inter
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-> SOLUTION: a sample of the reading scores of 29 fifth gtaders has a mean of x(with the bar on top of the x)=83 and a population standard deviation of r=10.5.
a. Find 99% confidence inter
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Question 281474: a sample of the reading scores of 29 fifth gtaders has a mean of x(with the bar on top of the x)=83 and a population standard deviation of r=10.5.
a. Find 99% confidence interval for the population mean scores of all fifth graders on this test.
b. How big should the sample size be for the margin of error to be no larger that 3.5?
c. 99% confidence interval if the sample was 29 fifth graders and you were given the sample standard deviation s=10.5 instead of the population standard deviation? Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! a sample of the reading scores of 29 fifth gtaders has a mean of x(with the bar on top of the x)=83 and a population standard deviation of r=10.5.
a. Find 99% confidence interval for the population mean scores of all fifth graders on this test.
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xbar = 83 ; s = 10.5, so s-hat = 10.5/sqrt(29) = 1.9498
invT(0.995,with df=28) = 2.7633
So, standard error for the population means = 2.7633*
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95% CI: 83-2.7633 < u < 83+2.7633
95% CI: 80.2367 < u < 85.7633
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b. How big should the sample size be for the margin of error to be no larger that 3.5?
n = [1.96*10.5/3.5]^2 = 34.57
Rounding up: n = 35
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c. 99% confidence interval if the sample was 29 fifth graders and you were given the sample standard deviation s=10.5 instead of the population standard deviation?
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