The average number of prisoners in a county jail is modeled by y = 0.15x2 + 10.34x + 122.54, where x is the number of years after 2000.
a. Graph this function from 0 to 30.
b. Approximate, to the nearest whole number, how many prisoners there will be in 2010.
c. Does this model indicate that the number of prisoners will increase or decrease from 2000 to 2030?