Table 14-1 on page 655 lists process data consisting of the errors (ft) of aircraft altimeters when they are tested for an altitude of 2000 ft, and the Federal Aviation Administration requires that errors must be at most ± 30 ft. If x and R control charts show that the process of manufacturing altimeters is within statistical control, does that indicate that the altimeters have errors that are at most ± 30 ft? Why or why not?

Table 14-1: