In a hypothesis test for the population variance the hypothe

In a hypothesis test for the population variance, the hypotheses to be tested are H0: sigma^2 =25 vs. Ha: sigma^2 < 25

(note: sigma is the circle thing with a tail on the top, also known as the population standard deviation)

If the sample size is 20 and the test is being carried out at the 10% level of significance, the null hypothesis will be rejected if:

A. Chi Squared > 12.4426

B. Chi Squared > 10.851

C. Chi Squared > 11.6509

D. Chi Squared > 10.117

Solution

As

df = n - 1 = 19

and it is a left tailed 0.10 level test, then by table/technology,

chi^2(crit) = 11.6509

Hence,

OPTION C: C. Chi Squared > 11.6509 [ANSWER]