Question

Which of the following can affect power?

a. using a two-tailed test instead of a one-tailed test
b. the sample size
c. alpha
of the above

Answer 1

The power of a test can be affected by whether a one-tailed or two-tailed test is used, the sample size, and the level of alpha. Larger sample sizes and appropriate alpha levels help increase test power.

Step-by-step explanation:

The factors that can affect the power of a test include:

• Using a two-tailed test instead of a one-tailed test can affect power since the region of rejection for the null hypothesis is split between two tails, potentially requiring more evidence for a significant result.
• Sample size is a crucial factor in determining power. A larger sample size generally increases the power of the test because it reduces the standard error and makes the test more sensitive to detecting true effects.
• The chosen level of alpha (α) affects power. A lower alpha level (for example, 0.01) requires stronger evidence to reject the null hypothesis compared to a higher alpha level (for example, 0.05), which can impact the power of the test.

Overall, the power of a test is influenced by these factors, where the goal is often to achieve high power, which reflects a high probability of correctly rejecting a false null hypothesis.