Question

This Question: 12 pts 18 of 23 (16 complete) Use the given sample statistics to test the claim about the difference between two population means ?? and ?2 at the given level of sign ficance ? Claim ?.-P2, ? :0 0, Statistics. x 1-68, s,-51, n1 : 40 and x2-63, sz" 7.1. n2-55 Determine the critical value(s). Round to three decimal places as needed Use a comma to separate answers as needed) Determine the rejection region Select the correct choice below, and if necessary, il in any answer boxes to complete your choice Round to three decimal places as needed) ??.

Answer 1

Solution :

here we have to test the claim that two population means are not equal.So this is two tailed test.

Given that alpha = 0.01 .and as the test is two tailed , here we get two critical values.

Using standard normal table with alpha =0.01 , with corresponding area alpha/2 (0.005) and1-(alpha/2) =0.995 ,we get critical values as -2.576 and 2.576.

OR you can use excel command as ,=NORMSINV(0.005) and =NORMSINV(0.995) and get critical values.

critical values Zo = -2.576, 2.576.

To determine rejection region.

The correct option is A , as this is two tailed test we have two rejection regions.

So answer is ,

A . z < - 2.576 and z > 2.576