The table below shows the linear relationship between the number of people at a picnic and the total cost of the picnic. A two column table with five rows. The first column, Number of People, has the entries, 6, 9, 12, 15. The second column, Total Cost in dollars, has the entries, 52, 58, 64, 70.

Which statements about the function described by the table are true? Check all that apply.