I need help plssssssssss

Uhh this one is hard. so i know that  the mean number of hours of sleep students with a grade point average of 3.0–4.0 received each night was 6.8 which is more than the students with 2.0-3.0  sample mean is "a  selection taken from a larger group (the "population") so that you can examine it to find out something about the larger group" here the students with the grade point 2.0-3.0 is the sample mean and 3.0-4.0 but the population mean is the students altogether with the grade points 2.0-4.0. usually sample mean is slightly lesser than the population but since 3.0-4.0 has a greater mean than 2.0-3.0 then 3.0-4.0 is about the same than the sample mean for students with a grade point average 2.0-3.0. the results tend to support garret's theory