Problem:

Suppose that a researcher, using data on class size (CS)and average test scores from 103 third-grade classes, estimates the OLS regression

Testscore^=556.828-6.2274CS,R2=.09,SER=12.3.

(a) A classroom has 20 students. The regression's prediction for that classroom's average test score is( ) . (Round your response to two decimal places.)

(b) Last year a classroom had 17 students, and this year it has 21 students. The regression's prediction for the change in the classroom average test score is( ). (Round your response to two decimal places.)

(c) The sample average class size across the 103 classrooms is 22.90.The sample average of the test scores across the 103 classrooms is ( ) . (Hint: Review the formulas for the OLS estimators.) (Round your response to two decimal places.)

(d) The total sum of squares is( ). (Hint: Review the formulas for the R2 and SER.) (Round your response to one decimal place.)