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) Provide the linear regression equation 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.

y = 0.7399x + 18.989

y = 0.7399(83) + 18.989

y = 80.40

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?