6. Answer the following questions using the prompt. Thompson Photo Works purchased several new, highly sophisticated processing machines. The production department needed some guidance with respect to qualifications needed by an operator. Is age a factor? Is the length of service as an operator (in years) important? In order to explore further the factors needed to estimate performance on the new processing machines, four variables were considered: o X1 = Length of time an employee was in the industry o X2 = Mechanical aptitude test score o X3 = Prior on-the-job rating o X4 = Age o Y = Performance on the new machine Thirty employees were selected at random. Data were collected for each, and their performances on the new machines were recorded. The following multiple regression equation was estimated: Y = 11.6 + 0.4 X1 + 0.286 X2 + 0.112 X3 + 0.002 X4. a. How many dependent variables are there? Independent variables? b. What is the number 0.286 called? c. As X1 increases by 5 years, how much does estimated performance on the new machine increase? d. As X2 increases by 10 points, how much does estimated performance on the new machine increase?