Fitch was going to the gym and trying to bulk up. he'd use a scale at the gym to see if he had gained weight. The first week he weighed himself, the scale showed that he had gained 4 pounds. The next time he weighed himself, the scale showed a weight gain of 3 pounds. The third time he weighed himself, he showed a weight gain of 5 pounds. In truth, Fitch had gained 2 pounds each time he weighed himself. is it valid? is it accurate? is it reliable