The accounts payable of a company changed from $136,100 to $104,300 over the course of a year. this change represents a: select one: a. use of $31,800 of cash as investment activity. b. source of $31,800 of cash as an operating activity. c. source of $31,800 of cash as a financing activity. d. source of $31,800 of cash as an investment activity. e. use of $31,800 of cash as an operating activity.

The kamp family has twins, rob and rachel. both rob and rachel graduated from college 2 years ago, and each is now earning $50,000 per year. rachel works in the retail industry, where the mean salary for executives with less than 5 years' experience is $35,000 with a standard deviation of $8,000. rob is an engineer. the mean salary for engineers with less than 5 years' experience is $60,000 with a standard deviation of $5,000.