Studies have shown that watching too much television hurts school grades. Others argue that like books, television not only entertains, it also exposes a child to new information about the world. While watching too much television is harmful, a little bit may actually help. Researcher Matt Castle gathers information on the grade point average (GPA) of 28 middle school children and the number of hours of television they watched per week. A portion of the data is shown in the accompanying table. GPA Hours 3.24 19 3.10 21 3.31 4 Click here for the Excel Data File 3. Estimate a quadratic regression model where the GPA of middle school children is regressed on hours and hours- squared. (Negative values should be indicated by a minus sign. Round your answers to 4 decimal places.) l-nmm b. Is the quadratic term in this model justified? 0 Yes, based on the R2. 0 Yes, based on the significance of Hoursz. ONO, based on the R2. ONO, based on the insignificance of Hoursz. c. Find the optimal number of weekly hours of TV for middle school children. (Round coefficient estimates to at least 4 decimal places and final answer to 2 decimal places.) Optimal number of weekly hours I I