Answer to Question 1
The model specification for the given data can be represented as:
Y = medical costs
X1 = 1 if professional, 0 otherwise
X2 = 1 if technical, 0 otherwise
X3 = 1 if sales, 0 otherwise
X4 = 1 if managerial, 0 otherwise
X5 = 1 if female, 0 otherwise
Y = 0 + 1X1 + 2X2 + 3X3 + 4X4 + 5X5 + 6(X1X5 ) + 7(X2X5 ) + 8(X3X5 ) + 9(X4X5 )
Answer to Question 2
FALSE