Question

A university is concerned about the presence of grade​ inflation, which is defined as an increase in the average GPA of the​ institution's students over time without a comparable increase in academic standards. To investigate this​ phenomenon, the average GPA for the student body was recorded over the past 11​years, as shown in the table to the right. Construct a 90% confidence interval for the slope. LCL=    UCL=

​(Round to three decimal places as​ needed.)

​Year GPA

1           3.07

2            2.85

3            2.96

4           2.86

5            2.97

6             3.04

7               3.07

8               2.99

9                3.19

10               3.16

11                  3.15

Answer 1

from above LCL =0.010

UCL =0.039