(5 points) Using the data, the following equation is estimated

for the fall and second semester students:  (5 points) Using the data, the following equation is estimated for the fall and second semester students:   
where trmgpa is term GPA, crsgpa is a weighted average of overall GPA in courses taken, sat is SAT score and hsperc is graduating percentile in high school class (defined so that, for example, hsperc=5 means the top five percent of the class).  
 


 
 

-Dropping sat and hsperc from the equation gives  
 
Are sat and hsperc jointly significant in the original equation at the 5% level? Show your work. 

(5 points) Consider an equation to explain rent rates (rent)

in a college town. Using the data, the following equation is obtained by OLS:    
where rent is the average monthly rent paid on rental units in a college town in the United States, pop is the total city population, avginc is the average city income, and pctstu is the student population as a percentage of the total population.  
 

-Dropping avginc and pctstu from the equation gives  
 
Are avginc and pctstu jointly significant in the original equation at the 1% level? Show your work.