Assume that each sample is obtained by randomly selecting values from a population with a normal distribution In constructing confidence intervals for Iuml or Iuml 2, we use Table A 4 to find the critical values x2L and x2R, that table applies only to cases in which n curren 101, so the number of d...

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Assume that each sample is obtained by randomly selecting values from a population with a normal distribution.

Question:

Assume that each sample is obtained by randomly selecting values from a population with a normal distribution.
In constructing confidence intervals for Ïƒ or Ïƒ2, we use Table A-4 to find the critical values x2L and x2R, that table applies only to cases in which n ‰¤ 101, so the number of degrees of freedom is 100 or fewer. For larger numbers of degrees of freedom, we can approximate x2L and x2R by using

where k is the number of degrees of freedom. Construct the 95% confidence interval for Ïƒ by using the following sample data: The measured heights of 772 men between the ages of 18 and 24 have a standard deviation of 2.8 in.