In a study relating college GPA to time spent in various activities, a researcher distributes a survey to several students. The students are asked how many hours they spend each week in four activities: studying, sleeping, working, and leisure. Any activity is put into one of the four activities, so that for each student, the sum of hours in the four activities must be 168 (24*7). The researcher then creates the variable study, sleep, work, leisure as the ratio of the number of hours in each activity and 168 (for example if student i sleeps 56 hours per week, then sleepi = 56/168 = 0.333333). The researcher plans to run the following econometric model: GPA = β0 + β1study + β2sleep + β3work + β4leisure + u. (2) Is there anything wrong with this model? Is there a problem, how should you advice the researcher to fix it?