For a dichotomous treatment regression (X = 1 or 0), the mean outcome for the treated group (X = 1) is 35 and the mean outcome for the untreated group is 67. What will the slope of the regression line be?

Question

Quizplus · Accepted Answer

For a dichotomous treatment regression, the regression equation is: Y = b0 + b1X. Here, X = 1 for the treated group, X = 0 for the untreated group.

Given the mean outcome for the treated group = 35 and the mean outcome for the untreated group = 67.

Hence, b0 is the mean outcome for the untreated group when X=0 = 67.

Therefore, b1 can be calculated using the following formula:
b1 = (mean outcome for treated group - mean outcome for untreated group)/ (X=1 - X=0) = (35-67)/(1-0) = -32

Therefore, the slope of the regression line will be -32.

For a Dichotomous Treatment Regression (X = 1 or 0)