The length of a screw produced by a machine is normally distributed with a mean of 0.25 inches and a standard deviation of 0.01 inches. What percent of screws are between 0.24 and 0.26 inches? 68% 95% 99.7% 100%
I believe the answer would be C. Cause the deviation is so small most nails would be between there.
68% that is one standard deviation. Sigma +1 and sigma - 1