7.1 Using the data equat P SLEEP75.RAW (see also Problem 3.3), we obtain the estimated sleep 3,840.83.163 totwrk - 11.71 educ - 8.70 age REVIEW N (235.11) (.018) (5.86) +.128 age + 87.75 male (.134) (34.33) n = 706, R2 = .123, R = .117. (11.21) The variable sleep is total minutes per week spent sleeping at night, totwrk is total weekly minutes spent working, educ and age are measured in years, and male is a gender dummy. (i) All other factors being equal, is there evidence that men sleep more than women? How strong is the evidence? (ii) Is there a statistically significant tradeoff between working and sleeping? What is the estimated tradeoff? (iii) What other regression do you need to run to test the null hypothesis that, holding other factors fixed, age has no effect on sleeping?