Does the null hypothesis for a nondirectional alternative hypothesis differ from the null hypothesis for a directional alternative hypothesis? Explain.

I have no idea how to state the answer for this.

Depending on the level of significance used, usually P=.01 or P=.05 (to reject the Ho, null hypothesis) the values needed for a one-tailed test (directional) are lower than those for a two-tailed (nondirectional) test.

This should start you out. I hope it helps. Thanks for asking.

To understand whether the null hypothesis for a nondirectional alternative hypothesis differs from the null hypothesis for a directional alternative hypothesis, we need to first understand what these terms mean.

Null hypothesis (H0): It is a statement that assumes there is no significant difference or relationship between variables in a population. It acts as a baseline to compare against the alternative hypothesis.

Alternative hypothesis (HA): It is a statement that contradicts or opposes the null hypothesis. It suggests that there is a significant difference or relationship between variables in a population.

Nondirectional alternative hypothesis: This type of alternative hypothesis suggests that there is a difference or relationship between variables, but does not specify the direction of the difference.

Directional alternative hypothesis: This type of alternative hypothesis suggests that there is a difference or relationship between variables and specifies the direction of the difference.

Now, let's consider an example to better illustrate the difference in null hypotheses for both types of alternative hypotheses.

Suppose we want to determine whether a new drug has an effect on reducing blood pressure. We can express the null hypotheses for both the nondirectional and directional alternative hypotheses as follows:

For the nondirectional alternative hypothesis (two-tailed test):
H0: The new drug has no effect on reducing blood pressure.
HA: The new drug has a significant effect on reducing blood pressure.

For the directional alternative hypothesis (one-tailed test):
H0: The new drug has no effect on reducing blood pressure.
HA: The new drug reduces blood pressure significantly.

As evident, the null hypothesis (H0) remains the same for both types of alternative hypotheses. The difference lies in the alternative hypothesis (HA), where the nondirectional alternative hypothesis does not specify the direction of the effect, while the directional alternative hypothesis does.

In summary, the null hypothesis for a nondirectional alternative hypothesis does not differ from the null hypothesis for a directional alternative hypothesis. The difference lies in the alternative hypothesis, where the nondirectional alternative hypothesis does not specify the direction of the effect, while the directional alternative hypothesis does.