The article "Evaluation of Mobile Mapping Systems for Roadway Data Collection" (H. Karimi, A. Khattak, and J. Hummer, Journal of Computing in Civil Engineering, 2000:168-173) describes a system for remotely measuring roadway elements such as the width of lanes and the heights of traffic signs. For a sample of 160 such elements, the average error (in percent) in the measurements was 1.90 , with a standard deviation of 21.20. Is it plausible that the mean error measurement is equal to zero?