A new lаser instrument is used tо meаsure the length оf а city blоck. The process is repeated 20 times independently and the 20 measurements are recorded. The actual length of the city block is known to be 340 feet. The 20 measurements obtained with the laser instrument all fall within a narrow range of 339.5 to 340.5 feet. Which statement best describes the laser instrument in this situation?