In Spring 2017, data was collected from a random selection of STA 2023 students. One of the questions asked how many hours they had worked in the past 24 hours. For the 39 randomly selected upperclassmen, the sample mean was 0.61 and sample standard deviation was 2.32. For the 35 randomly selected underclassmen, the sample mean was 1.40 and the sample standard deviation was 2.65. What is the point estimate of the difference in the population mean hours worked between underclassmen and upperclassmen?

Isuck at math ; ^; m a student solved this problem and said the answer is 3 feet. chase had a roll of ribbon that contained 7 7/8  feet of ribbon. he cut off one piece that was 3 5/8  feet long and another piece that was 1 1/4  feet from the roll. how much ribbon was left on the roll? is the student's answer reasonable? yes, the answer is reasonable. no, the answer is not reasonable. it should be about 2 feet. no, the answer is not reasonable. it should be about 13 feet. no, the answer is not reasonable. it should be about 4 feet.