When a new charter school opened in 1994, there were 440 students enrolled. Write a formula for the function N(t), representing the number of students attending this charter school t years after 1994, assuming that the student population: Increased by 40 students per year N ( t ) = Decreased by 20 students per year N ( t ) = Increased by 36 students every 2 years N ( t ) = Decreased by 48 students every 4 years N ( t ) = Remained constant (did not change) N ( t ) =