Muscle Beach Incorporated makes three models of high-performance weight-training benches. Current operating data are summarized here: Reyuiteu. a. Calculate the contribution margin ratio of each product. b. Calculate the firm's overall contribution margin ratio. c. Calculate the firm's monthly breakeven point in sales dollars. d. Calculate the firm's monthly operating income. e. Management is considering the elimination of the ProForce model due to its low sales volume and low contribution margin ratio. As a result, total fixed expenses can be reduced to $267,830 per month. Assuming that this change would not affect the other models, what would be the effect on net operatin income. Would you recommend the elimination of the ProForce model? f. Assume the same facts as in requirement e-1. Assume also that the sales volume for the PowerGym model will increase by 505 units per month if the ProForce model is eliminated. What would be the effect on operating income. Would you recommend eliminating the ProForce model