Which function best models the data in the graph? y = - 10x + 55
y = 120 * (1/2) ^ x *
y = (x - 4) ^ 2 + 15
y = 60/x

y=60/x

Study results indicate that the mean length of time people spend on a bus in a city is between 21.2 min and 24.5 min what is the study margin of the error?