You are working part-time at a road construction firm. Your boss knows you are learning some statistics in your classes this semester and calls you into the office. He says, “We’ve taken sample densities from loads of asphalt we’ve gotten from our supplier. The information from their company says their process produces a consistent density with a standard deviation of 2.65 pounds per cubic foot. Here’s the data we’ve collected. Can you give me an estimate of the average density that our supplier’s process is producing? I want to be 80% confident of the range you provide.”
You are working part-time at a road construction firm. Your boss knows you are learning some...
Make sure to include Given, Find, etc. No diagrams = no credit. Problem 1. For a normal population with known variance 2, what is the confidence level for the CI x ̅-2.14/√n≤μ≤x ̅+2.14/√n ? Problem 2. An electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed with a standard deviation of 40 hours. If a sample of 30 bulbs has an average life of 780 hours, find a 96% confidence interval for the...