College Graduation Rates. Data from the CollegeResults Online website compared the 2011 graduation rate and medianSAT score for 92 similar-sized public universities and colleges inthe United States. The scatterplot below shows the relationshipbetween these two variables along with the least squares fit. Roundall calculated results to 4 decimal places.
1. The relationship between median SAT score and graduation rateis  ? positive negative ,  ? weak strong ,and  ? linear non-linear .
2. The explanatory variable is  ? graduation ratemedian SAT college year  and the response variableis  ? graduation rate median SAT college year .
The summary statistics for graduation rate and median SAT scoreare listed below. The correlation between graduation rate andmedian SAT score is 0.663.
Median SAT score: mean = 1030.3, standard deviation = 80.7
Graduation rate: mean = 49.6, standard deviation = 14.3
3. The equation of the regression line is y=Â Â +Â Â x
4. Complete the following sentence to interpret the slope of theregression line:
An increase of  in Median SAT score corresponds toa/an  ? decrease increase  of  inGraduation Rate.
5. The recorded median SAT score for Northern MichiganUniversity is 1026. Use the regression equation to estimate thegraduation rate for Northern Michigan University.
6. The recorded graduation rate for Northern Michigan Universityis 46.3. Complete the following sentence.
The residual for Northern Michigan University is  .This means the graduation rate at Northern Michigan Universityis
A. lower than
B. higher than
C. the same as
the rate predicted by the regression model.
7. Stanford University (an elite private university inCalifornia not included in this data set) has a median SAT score of1455. Would it be appropriate to use this linear model to predictthe graduation rate for Stanford?
A. Yes, because 1455 is a reasonable median SATscore for an elite university.
B. No, because 1455 is beyond the range of thedata used to build the regression model.
C. No, because 99.495% is too large to be areasonable graduation rate, even for an elite university.
