1. Tracy and Eric are timing how fast marbles roll down an inclined plane. They plan to do this 5 times, and then take the average time for their
results. What would be the BEST way to improve the accuracy of their
data?

A) Include marbles of three different colors in their investigation

B) Include the average of 20 trials down the inclined plane

C) Use marbles of 10 different densities

D) Use toy cars instead of marbles