The length of a rod was measured eight times. The measurements in centimeters, in the order they were taken, were 21.20, 21.22, 21.25, 21.26, 21.28, 21.30, 21.32, 21.35.
a) Do these measurements appear to be a random sample from a population of possible measurements? Why or why not?
b) Is it possible to estimate the uncertainty in these measurements? Explain.