Which of the following are examples of one-tailed tests in hypothesis testing?

• A. A test where the alternative hypothesis is $H:\mu =10$
• B. A test where the alternative hypothesis is $H:\mu >10$
• C. A test where the alternative hypothesis is $H:\mu <10$
• D. A test where the alternative hypothesis is $H:\mu \ne 10$

Answer: (C)

Verified step by step guidance

1. Understand that a one-tailed test in hypothesis testing is used when the alternative hypothesis specifies a direction of the effect, either greater than or less than a certain value.
2. Identify the form of the alternative hypothesis (H\colon \mu > 10) which indicates a right-tailed test because it tests if the mean is greater than 10.
3. Identify the form of the alternative hypothesis (H\colon \mu < 10) which indicates a left-tailed test because it tests if the mean is less than 10.
4. Recognize that the alternative hypothesis (H\colon \mu \neq 10) represents a two-tailed test because it tests for any difference from 10, either greater or less, without specifying direction.
5. Conclude that the examples of one-tailed tests are those where the alternative hypothesis is either H\colon \mu > 10 or H\colon \mu < 10.