A population of values has a normal distribution with ,u = 173.8 and a = 39.5. You intend to draw a random sample of size n = 215. What is the mean of the distribution of sample means? \"Fl: What is the standard deviation of the distribution of sample means (i.e. the standard error)? (Report answer accurate to 2 decimal places.) =[:] A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 129- cm and a standard deviation of 1.5-cm. For shipment, 17 steel rods are bundled together. Find the probability that the average length of a randomly selected bundle of steel rods is between 128.2- cm and 129.9-cm. P(128.2-cm