Question

Estimate: GPA = β0 + β1GRE + ε, where GRE is a student’s score on the math portion of the Graduate Record Examination (GRE) score and GPA is the student’s grade point average in graduate school.

GPA	GRE
3.9	690
3.2	740
3.1	740
2.7	650
2.5	700
2.9	640
2.7	710
2.9	700
2.1	760
2.3	670
3.6	750
2.5	700
3.4	650
3.9	690
3.3	700
2.7	680
3.8	660
2.6	660
3.9	710
3.8	760
3	690
3.2	710
3.1	750
2.2	760

a. Use R’s predict() function to construct the 90% confidence interval for the expected GPA for an individual who scored 720 on the math portion of the GRE. (Round answers to 2 decimal places.)

b. Use R’s predict() function to construct the 90% prediction interval for GPA for an individual who scored 720 on the math portion of the GRE. (Round answers to 2 decimal places.)

Answer 1