A sample of 21 elements is selected to estimate a 90% confidence interval for the variance of the population.The chi-square value(s) to be used for this interval estimation is(are)

A) 31.410.
B) 12.443.
C) 10.851 and 31.410.
D) 12.443 and 28.412.

Question

Gursagar Dhami · Accepted Answer

Final Answer : C, Explanation :  The chi-square distribution with 20 degrees of freedom at 0.05 level of significance is 31.410.The chi-square distribution with 20 degrees of freedom at 0.10 level of significance is 23.209.To estimate a 90% confidence interval for the variance of the population, we need to find the chi-square values that enclose 90% area under the curve of the chi-square distribution with n-1 degrees of freedom. Using a chi-square calculator, we find that the chi-square value with area 0.05 to the right is 10.851 and the chi-square value with area 0.05 to the left is 31.410. Therefore, the best choice is C.

A sample of 21 elements is selected to estimate a 90% confidence interval for the variance of the population.The chi-square value(s) to be used for this interval estimation is(are)

A) 31.410.
B) 12.443.
C) 10.851 and 31.410.
D) 12.443 and 28.412.

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A sample of 21 elements is selected to estimate a 90% confidence interval for the variance of the population.The chi-square value(s) to be used for this interval estimation is(are) A) 31.410.B) 12.443.C) 10.851 and 31.410.D) 12.443 and 28.412.

Definitions

Learning Objectives

Learning Objectives

Related questions

A sample of 21 elements is selected to estimate a 90% confidence interval for the variance of the population.The chi-square value(s) to be used for this interval estimation is(are)

A) 31.410.
B) 12.443.
C) 10.851 and 31.410.
D) 12.443 and 28.412.