Arsha predicted that she would sell 225 magnets. She actually sold 240 magnets. What are the values of a and b in the table below? a = -15 / 225 ; b = - 6.7 percent
a = - 15 over 240; b = - 6.25 percent
a = 15 over 240 ; b = 6.25 percent
a = 15 over 225 ; b = 6.7 percent