Smoking levels: According to the Centers for Disease Control and Prevention, the proportion of U. S. adults age 25 or older who smoke is .22. A researcher suspects that the rate is lower among U. S. adults 25 or older who have a bachelor's degree or higher education level. What is the alternative hypothesis in this case? Group of answer choices a. The proportion of smokers among U. S. adults 25 or older who have a bachelor's degree or higher is less than .22. b. The proportion of smokers among U. S. adults 25 or older who have a bachelor's degree or higher is .22. c. The proportion of smokers among U. S. adults 25 or older who have a bachelor's degree or higher is not .22. d. There is a relationship between level of education level and smoking habits.

The correct option is (a).

Step-by-step explanation:

According to the Centers for Disease Control and Prevention, 0.22 or 22% of US adults of 25 years or older smoke.

But a researcher suspects that this percentage is lower if the US adults of 25 years or older have a bachelor's degree or higher education level.

So, the researcher needs to test whether the proportion of US adults  of 25 years or older who smoke is less in case the adults have bachelor's degree or higher.

To test his suspicion the researcher can use a one-proportion z-test.

The hypothesis of the test can be defined as:

H₀: The proportion of smokers among US adults of 25 years or older who have a bachelor's degree or higher is 0.22, i.e. p = 0.22.

Hₐ: The proportion of smokers among US adults of 25 years or older who have a bachelor's degree or higher is less than 0.22, i.e. p < 0.22.

Thus, the correct option is (a).