Rocco Is on the Championship Wrestling Team, and Right Before

Multiple Choice

Rocco is on the championship wrestling team, and right before his match the coach must weigh him. Rocco gets on the scale the first time and it reads 175.7 lbs. He doesn't think that sounds correct so he weighs himself again, on the same scale, and it reads 176.3 lbs. Rocco's coach requests a third weigh-in and the scale reads 175.2 lbs. This unpredictable variation in Rocco's weight is best explained by:

A) standardization.
B) systematic error.
C) bias.
D) random error.