21. Mile markers will tell you how far you have traveled on any interstate while in that state. Consider the chart below that relates the time in minutes and the distance in miles that a car has traveled in New York. 0 25 65 100 Time in NY, (minutes) Mile marker, m , (miles) 0 30 78 120 (a) What is the constant of proportionality (b) Write an equation that relates the time, for this relationship in miles per minute? t, and miles, m. Solve it for m. 78 20 GS 20 ) + 30, . (C) If this car traveled for two and a half hours in New York, how far will it have gone?