Question

1. When a value of Y is calculated using the regression equation (Y_hat), it is called:

-the fitted value

-the estimated value

-the predicted value

-all of the above

2. In the simple linear regression model, the y-intercept (normally referred to as "a" or "b0" in our regression model) represents the:

-change in y per unit change in x

-change in x per unit change in y

-value of y when x = 0

-value of x when y = 0

3. In the simple linear regression model, the slope (normally referred to as "b" or "b1" in our regression model) represents the:

-value of y when x = 0

-change in y per unit change in x

-value of x when y = 0

-change in x per unit change in y

4. Use Excel to calculate for the following dataset:

X	Y
1	10
1	12
3	13
3	17
5	17
5	21

the correlation coefficient:   Please round to two decimals

the value of the intercept, b0:  

the value of the slope, b1:    

the predicted value of Y when X =5:

Answer 1

1. When a value of Y is calculated using the regression equation (Y_hat), it is called:

-the predicted value

2. In the simple linear regression model, the y-intercept (normally referred to as "a" or "b0" in our regression model) represents the:

-value of y when x = 0

3. In the simple linear regression model, the slope (normally referred to as "b" or "b1" in our regression model) represents the:

-change in y per unit change in x

4.

X	Y
1	10
1	12
3	13
3	17
5	17
5	21

correlation in excel:

CORREL(A1:A6,B1:B6)

0.88

Answer:- 0.88

b1 in excel

b1 = r * ( sy / sx )

CORREL(A2:A7,B2:B7) * ( STDEV.P(B2:B7) / STDEV.P(A2:A7))

2

Answer:- b1 = 2

bo= ?

b0 = ymean - b1(xmean)
AVERAGE(B2:B7) - ( 2* AVERAGE(A2:A7))	= 9

bo = 9

The regression equation is y = 9 + 2*x

when x= 5

y = 9 + 2*5

= 9 + 10

= 19

y= 19 for x = 5