The number of species of coastal dune plants in Australia decreases as the latitude, in ^◦S, increases. There are 34 species at 11^◦S and 26 species at 44^◦S.

(a) Find a formula for the number, N, of species of coastal dune plants in Australia as a linear function of the latitude, t, in ^◦S. 

(b) Give units for and interpret the slope and the vertical intercept of this function. 

(c) Graph this function between t = 11^◦S and t = 44^◦S. (Australia lies entirely within these latitudes.)