A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 212.8-cm and a standard deviation of 1.2-cm. For shipment, 21 steel rods are bundled together. Find the probability that the average length of a randomly selected bundle of steel rods is greater than 213.1-cm.
P(M > 213.1-cm) =
Enter your answer as a number accurate to 4 decimal places. Answers obtained using exact z-scores or z-scores rounded to 3 decimal places are accepted