An Educator Wanted to Look at the Study Habits of University

Multiple Choice

An educator wanted to look at the study habits of university students. As part of the research, data was collected for three variables - the amount of time (in hours per week) spent studying, the amount of time (in hours per week) spent playing video games and the GPA - for a sample of 20 male university students. As part of the research, a 95% confidence interval for the average GPA of all male university students was calculated to be: (2.95, 3.10) . What assumption is necessary for the confidence interval analysis to work properly?

A) The Central Limit theorem guarantees that no assumptions about the population are necessary.
B) The population that we are sampling from needs to be a t-distribution with n-1 degrees of freedom.
C) The sampling distribution of the sample mean needs to be approximately normally distributed.
D) The population that we are sampling from needs to be approximately normally distributed.