Question

Christine is the dean of students at a college. She is concerned about the amount of sleep students are getting. In particular, Christine is making an inquiry on whether students who are enrolled in the pre-med program are getting less sleep on average compared to students who are enrolled in other programs. The average amount of sleep per night for a random sample of 10 pre-med students and 10 students in other programs is recorded. Assume that the population standard deviation of hours of sleep per night is 0.6 hour for the pre-med students and 0.8 hour for the students in other programs, and that the number of hours of sleep per night for both groups of students is normally distributed. Let the pre-med students be the first sample, and let the other students be the second sample. She conducts a two-mean hypothesis test at the 0.05 level of significance, to test if there is evidence that pre-med students are getting less sleep than students in other programs.

H0:μ1=μ2; Ha:μ1≠μ2, which is a two-tailed test.

H0:μ1=μ2; Ha:μ1<μ2, which is a left-tailed test.

H0:μ1=μ2; Ha:μ1>μ2, which is a right-tailed test.

H0:μ1≠μ2; Ha:μ1=μ2, which is a two-tailed test.

Answer 1