In the aftermath of a hurricane, an entrepreneur took a one-month leave of absence (without pay) from her $4,000 per month job in order to operate a kiosk that sold fresh drinking water. During the month she operated this venture the entrepreneur paid the government $2,000 in kiosk rent and purchased water from a local wholesaler at a price of $1.23 per gallon. bay75969_ch05_155-201.qxd 7/31/09 9:45 AM Page 197 Confirming Pages 198 Managerial Economics and Business Strategy Write an equation that summarizes the cost function for her operation, as well as equations that summarize the marginal, average variable, average fixed, and average total costs of selling fresh drinking water at the kiosk.