Question

The answer choices below represent different hypothesis tests. Which of the choices are left-tailed tests? Select all correct answers. Select all that apply: H0:X=17.3, Ha:X≠17.3 H0:X≥19.7, Ha:X<19.7 H0:X≥11.2, Ha:X<11.2 H0:X=13.2, Ha:X≠13.2 H0:X=17.8, Ha:X≠17

Answer 1

A hypothesis test where the rejection region lies in the extreme left of the curve(or distribution) , is called a Left-tailed Test, i.e. when the alternate hypothesis is of the form H_a: X< n , where n is some numerical quantity.

According to the question, the first choice is

Clearly, the alternate hypothesis would lie on both side of the curve which calls for a both-tailed test.

The second choice is

This alternate hypothesis highlights the left side of the curve as rejection region. Hence, it will represent a left-tailed test .

The third choice is

Here also, alternate hypothesis highlights the left side of the curve as rejection region. Hence, it will represent a left-tailed test .

The fourth choice is

Clearly, the alternate hypothesis would lie on both side of the curve which calls for a both-tailed test.

The fifth choice is

Here also, the alternate hypothesis would lie on both side of the curve which calls for a both-tailed test.