The focus sample contains information of the undergraduate students at the University of Wisconsin. Open Focus samples worksheet:
a) Find the linear correlation coefficient between cumulative GPA and high school percentile for the 200 UWEC undergraduate students in the Focus sample
b) Repeat part (a) for cumulative GPA and each of ACT English score, ACT math score, and ACT composite score.
c) Among the variables high school percentile, ACT English score, ACT math score, and ACT composite score, identify the one that appears to be the best predictor of cumulative GPA. Explain your reasoning.
Now perform a regression analysis on cumulative GPA, using the predictor variable identified in part (c), as follows.
d) Obtain and interpret a scatterplot.
e) Find and interpret the regression equation.
f) Find and interpret the coefficient of determination.
g) Determine and interpret the three sums of squares SSR, SSE, and SST.
Variable Variable name
High School percentile HSP
Cumulative GPA GPA
Total earned credits CREDITS
Primary major MAJOR
Admission type TYPE
ACT English score ENGLISH
ACT math score MATH
ACT composite score COMP
The solution gives detailed steps on conducting a complete regression analysis using ACT score example. All work has been done in Excel.