Question 1.

A simple linear regression model for marks (Yi) and the hours of study (Xi) is as follows: Yi =0 +1 Xi +ei

where 0 and 1 are unknown parameters, and ei is the disturbance term. The regression results are:

Regression Statistics___________

	Coefficient	Standard error	t Stat	p-value
Intercept	50	2.00	A	0.01
Study hours	B	0.50	4	0.05

R Square Standard error Observations

0.8643 9.4531

 30 __________________________ 

1. a) What are the values of A and B?
2. b) Explain the meaning of R Square.
3. c) What conclusions can you reach about the relationships between marks (Yi) and study hours (Xi)?
4. d) What is the predicted marks for a person with 20 hours of study?
5. e) Is this prediction reliable?
6. f) Find and interpret the value of the coefficient of determination. Question 7.

A simple linear regression model for salary (Yi) and the number of years of working (Xi) is as follows:

Yi =0 +1 Xi +ei where 0 and 1 are unknown parameters, and ei is the disturbance term. The regression results are:

Regression Statistics___________

	Coefficient	Standard error	t Stat	p-value
Intercept	100	A	5.00	0.005
Working years	B	0.50	10.00	0.05

R Square Standard error Observations

0.8643 9.4531

 30 __________________________

1. a) What are the values of A and B? Explain.
2. b) Explain the meaning of R Square.
3. c) What conclusions can you reach about the relationships between salary (Yi) and working years (Xi)?
4. d) What is the predicted salary for a person with 10 years working experience?
5. e) Is this prediction reliable?