Question

Determine the critical values for these tests of a population standard deviation.

​1.A​ right-tailed test with 19 degrees of freedom at the a=0.1 level of significance

​2. A​ left-tailed test for a sample of size n= 23 at the a= 0.01 level of significance

​2. A​ two-tailed test for a sample of size n= 30 at the a=0.01 level of significance

Answer 1

	df, ,tails	excel function	chi square critical value
1	19 , = 0.1, right tailed test	=CHISQ.INV.RT(0.1,19)
2	(n-1) = (23-1)= 22 = 0.01 left tailed test	=CHISQ.INV(0.01,22)
3	(n-1) = (30-1) = 29 = 0.01 both tailed test	=CHISQ.INV(0.005,29)
		=CHISQ.INV(0.995,29) or you can directly enter =CHISQ.INV.RT(0.005,29)

i have showed you the excel functions here, but you can also use the chi square distribution tables to find out the critical values.

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