Dana owns her own reai 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 lislings over the last several months. However. Dana 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

$\backslash$table$[[$Manth$,\backslash$table$[[$Number of$],[$Listings$]],\backslash$table$[[$Advertising$],[$Cosi$]]],[$March$,22,$$$15\mathrm{.}280$