Nancy owns her own real estate agency. She has been working hard to increase her client base. She offers the most comprehensive advertising campaign in the city and it has been paying off by the steady increase in the number of listings over the last several months. However, Nancy is concerned that her extensive cost for advertising is eating into her profits. It is difficult to determine how much she spends on advertising for each listing because some of her advertising sources are fixed amounts each month and others are more variable in nature. She would like to analyze the following information to determine how her advertising costs behave based on the number of listings. Month March April May June July August September October November Number of Listings 23 26 39 41 48 53 52 58 55 Advertising Cost 15220 17680 23175 27230 30510 32550 31835 36045 34890 If Dana believes she will have 54 listings in December, what is her expected cost for advertising?