Topic 3:

Book: Operations and Supply Chain Management Jacobs & Chase 14e

Students in a science class have just received their grades on the first test. The instructor has provided information about the first test grades in some previous classes as well as the final average for the same students. Some of these grades have been sampled and are as follows:

Student	1	2	3	4	5	6	7	8	9
1st Test Grade	98	77	88	80	96	61	66	95	69
Final Average	93	78	84	73	84	64	64	95	76

You are also provided the results from several different linear regression relationships for the above data. These provide different regression relationships looking at different combination of independent and dependent variables.

a) Develop a linear regression model that can be used to predict the final course average based on the first test grade.

b) Predict the final average of a student who made an 83 on the first test.

c) Would you recommend using this relationship for forecasting the final averages? Why? Also, explain how strong the relationship is between these two variables.

d) Suppose a student scored a 38 on the first test. Predict the final average of a student who had this score? What cautions would you recommend about using the linear regression relationship for predicting a final average?

Students in a science class have just received their grades on the first test. The instructor has provided information about the first test grades in some previous classes as well as the final average for the same students. Some of these grades have been sampled and are as follows: 5 Student Ist Test Grade Final Average 7 66 61 98 93 88 84 80 73 96 84 8 95 95 9 69 76 You are also provided the results from several different linear regression relationships for the above data. These provide different regression relationships looking at different combination of independent and dependent variables. Regression Independent Dependent Variable Value of b . Value of a Coefficient of Relationship Variable (slope) fy-intercept) Determination, r? Regression 1 Student Final Average -1.10 84 50 0.07 Regression 2 Final Average First Test Grade 1.15 -9.37 0.85 Regression 3 Student First Test Grade -2.08 9153 0.17 Regression 4 First Test Grade Final Average 0.74 18.99 0.85 Regression 5 Final Average Student -0.07 10.22 0.07 a) Develop a linear regression model that can be used to predict the final course average based on the first test grade. b) Predict the final average of a student who made an 83 on the first test. D Focus to search