4. A group of students in a statistics course have been asked to guess what grade they expect to

get on a particular exam. A regression equation is to be fit using the actual grade as the dependent

variable (Y) and the guess as the independent variable (X). The data for a group of ten such

students follows:

Student

Exam Grade (Y)

Guess (X)

X

2

XY

Y

2

A

65

65

4225

4225

4225

B

55

60

3600

3300

3025

C

50

60

3600

3000

2500

D

44

58

3364

2552

1936

E

71

65

4225

4615

5041

F

76

78

6084

5928

5776

G

43

35

1225

1505

1849

H

82

77

5929

6314

6724

I

77

84

7056

6468

5929

J

53

50

2500

2650

2809

Total:

616

632

41808

40557

39814

(a) Compute the estimate of 0 and 1 and write down the estimated regression line.

(b) What will be the estimated grade for a person who guessed that his exam grade will be 70.