A professor is interested in the study habits of full-time students at a university. The researcher wants to know if students study the recommended minimum of one hour of outside class study time for each hour spent in class. To test his prediction the researcher surveys 10 students and asks the students how many hours they typically study in a week. All of the students are enrolled in 5, 3-unit courses, so the students should study at least 15 hours per week outside of class.

A researcher is interested in increasing the power of their study, the researcher decides to make two changes in their study to increase power, (a) they decide to run a directional test, and (b) they decide to double their sample size.

(1) Explain how running a directional test will increase the power of the study.

(2) Explain how doubling the sample size will increase the power of the study.