Biddle and Hamermesh (1990) built a multiple regression model to study the tradeoff between time spent in sleeping and working and to look at other factors affecting sleep: Sleep = ?0 + ?1 totwrk + ?2 educ + ?3 age + ? where sleep and totwrk (total work) are measured in minutes per week and educ and age are measured in years. Suppose the following equation is estimated: Sleep = 3500 0.15 totwrk 11.20 educ + 2.29 age + ?
