1.Consider the following data with the dependent variable y, independent variable x, and the dummy variable d.

Y d x Y d x

100 0 9.3 70 1 9.1

100 0 6.5 100 0 8.9

50 0 4.2 40 0 5.4

75 1 7.4 90 0 8.8

65 0 6 75 1 8.8

90 0 7.6 40 1 5

85 1 9.6 45 1 6.5

65 1 6.5 55 0 5.2

50 1 6 100 0 10

75 1 9.9 90 0 8.4

75 1 8.6 80 1 6.4

65 0 4.9 80 0 6.7

95 0 7.2 90 1 8.5

95 0 9.9 60 0 5.9

90 1 7.8 95 1 8.9

80 1 7.2 45 0 6.3

75 0 7 65 0 7.5

95 0 8.7 85 1 6.8

100 1 9.9 60 1 5.7

90 1 9.3 75 1 4.5

The output for multiple linear regression model is created as following:

Table 5:

Coefficients Standard Error t Stat P-value Lower 95% Upper 95%

Intercept 19.92 9.41 2.12 0.04 0.86 38.98

d -5.95 4.09 -1.46 0.15 -14.24 2.34

x 8.01 1.24 6.46 0 5.5 10.52

Table 6

Multiple R. 0.73

R Square. 0.53

Adjusted R Square. 0.51

Standard Error. 12.84

Observations. 40.00

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