IV. (20 points) Three different assembly methods have been proposed for a new product.An experiment design was chosen to determine which assembly method results in the greatest number of parts produced per hour, and 15 workers were randomly selected and assigned to use one of the proposed methods. The number of units produced by each worker follows. Take it as an example to answer the following questions. Method A Method B Method C 97 193 99 73 77 59 (1)If multiple regression approach is used to solve the problem of experimental design, how to define dependent variable and independent variables? (2)If regression analysis is considered, how to make arrangements of the original data? (3)what type of model will be built? (4)how can we use the output from the multiple regression analysis to perform the ANOVA test on the difference among the means for the three methods