Source DF Seq SS. Using MINITAB solution, answer the following questions.

X1 1 401.42

X2 1 0.12

X3 1 20.67

D 1 4.28

Using MINITAB solution, answer the following questions.

a) Write the estimated regression equation.

b) Explain the meaning of obtained by estimating the given regression model.

c) What is the predicted value of y for ; ; ; and

d) Construct a 99% confidence interval for the coefficient of .

e) Using the 5% significance level, test the null hypothesis that the coefficient of is zero against two-sided alternative.

4. The salaries of workers are expected to be depending on the number of years they have spent in school and their work experience. The following table gives information on annual salaries (in thousands of dollars), number of years of studying, and years of experience for 10 persons. It also includes information on gender. In the table, M represents males and F refers to females.

Salary
Studying
Experience
Gender	F	F	M	M	F	F	M	M	F	M

Using MINITAB (or any other statistical software package), find the regression of salary on studying, experience, and gender. Then answer the following questions.

a) Write the estimated regression equation.

b) Explain the meaning of the estimated regression coefficient of the dummy variables.

c) By estimating the regression model with gender as a dummy variable, you have actually estimated two regression models-one for males and the other for females. Write these two regression equations.

d) How much salary is a male worker with 18 years of studying and 7 years of work experience expected to earn?

e) How much salary is a female worker with 18 years of studying and 7 years of work experience expected to earn?

f) Determine a 95% confidence interval for the coefficient of dummy variable.

g) Using the 5% significance level, can you conclude that female workers are paid lower salaries than male workers?

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