The probability that no more than 4 vehicles will change lanes is 50.71%.
Since the probability that a vehicle will change lanes while making a turn is 55%, supposing a random sample of 7 vehicles are observed making turns at a busy intersection, to find the probability that no more than 4 vehicles will change lanes while making the turn, the following calculation must be performed:
((0.55 x 4) + (0.45 x 3)) / 7 = X
0.5071 = X
Therefore, the probability that no more than 4 vehicles will change lanes is 50.71%.