A random sample of n = 9 structural elements is tested for compressive strength. We know that the true mean compressive strength is 5500 psi while the sample standard deviation is 1000 psi. The interest is to find the probability that the sample mean compressive strength exceeds 4985 psi. Solve this problem first using the standard normal distribution (Z) and then using the T distribution. What are the differences between the answers when using Z vs. T. Do the differences make sense?