In what follows use any of the following tests/procedures: regression, confidence intervals, one-sided t-test, or two-sided t-test. all the procedures should be done with 5% p-value or 95% confidence interval. the empirical literature suggests that class absenteeism undermines students’ academic performance and that an enforced mandatory attendance policy may be beneficial. open attendance data. using data on 90 second-year students enrolled in a statistics course, test if students who are assiduous in attending lectures have higher final grades than students who are usually absent.

To save energy, the air supply to a 2000 ft office has been shut off overnight and the room temperature has dropped to 40°f. in the morning, the thermostat is reset to 70°f and warm air at 120 f begins to flov in at 200ft'/min. the air is well mixed within the room, and an equal mass flow of air at room temperature (changing with time) is withdrawn through a return duct. the air pressure is nearly 1 atm everywhere. ignoring heat transfer with the surroundings and kinetic and potential energy effects, estimate how long it takes for the room temperature to reach 70°f. plot the room temperature as a function of time.