EXERCISE 4-13. Rhetorix, Inc., produces stereo speakers. The selling price per pair of speakers is $1,000. The variable cost of production is $300 and the fixed cost per month is $49,000.

a. Calculate the contribution margin associated with a pair of speakers.

b. In August, the company sold eight more pairs of speakers than planned. What is the expected effect on profit of selling the additional speakers?

c. Calculate the contribution margin ratio for Rhetorix associated with a pair of speakers.

d. In October, the company had sales that were $10,000 higher than planned. What is the expected effect on profit related to the additional sales?

Please show all steps. Thank you.