In: Statistics and Probability
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. [You may find it useful to reference the t table.]
| GPA | GRE | 
| 2.8 | 750 | 
| 3.4 | 670 | 
| 2.5 | 780 | 
| 3.4 | 680 | 
| 2.8 | 720 | 
| 3.7 | 770 | 
| 2.4 | 750 | 
| 2.6 | 760 | 
| 3.8 | 680 | 
| 2.7 | 740 | 
| 2.7 | 680 | 
| 3.1 | 640 | 
| 3 | 710 | 
| 2.6 | 710 | 
| 3.2 | 700 | 
| 3.5 | 750 | 
| 3.9 | 700 | 
| 2.5 | 660 | 
| 2.9 | 740 | 
| 3.5 | 660 | 
| 2.1 | 760 | 
| 2.7 | 660 | 
| 3.8 | 650 | 
| 2.5 | 670 | 
a. Construct the 90% confidence interval for the
expected GPA for an individual who scored 730 on the math portion
of the GRE. (Round regression estimates to at least 4
decimal places, "tα/2,df"
value to 3 decimal places, and final answers to 2 decimal
places.)
b. Construct the 90% prediction interval for GPA
for an individual who scored 730 on the math portion of the GRE.
(Round regression estimates to at least 4 decimal places,
"tα/2,df" value to 3
decimal places, and final answers to 2 decimal
places.)