Question

The difference of sample means of two populations is 55.4, and the standard deviation of the difference of sample means is 28.1. Which statement is true if we are testing the null hypothesis at the 95% confidence level? Medals 0

Answer Choices:

The difference of the two means is significant, so the null hypothesis must be rejected.

The difference of the two means is significant, so the null hypothesis must be accepted.

The difference of the two means is not significant, so the null hypothesis must be rejected.

The difference of the two means is not significant, so the null hypothesis must be accepted.

Answer 1

Explanation:

The difference of sample means of two populations is 55.4, and the standard deviation of the difference of sample means is 28.1.

At 95% level, z value =1.96

Margin of error =1.96*28.1=55.076

But difference of means >55.076

Hence conclusion would be

The difference of the two means is significant, so the null hypothesis must be rejected.

Answer 2

since if we are testing the null hypothesis at the 95% confidence level is that the difference of the two means is not significant at the 95% confidence level, so the null hypothesis must be rejected.

Hence option 3) is correct.