1. A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 125.2-cm and a standard deviation of 2.3-cm. For shipment, 25 steel rods are bundled together.
Find the probability that the average length of a randomly selected bundle of steel rods is less than 124.5-cm.
P(M < 124.5-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.
2. A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 168.5-cm and a standard deviation of 1.2-cm. For shipment, 24 steel rods are bundled together.
Find the probability that the average length of a randomly selected bundle of steel rods is between 168.3-cm and 169-cm.
P(168.3-cm < M < 169-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.