Graziano Construction has received a large shipment of steel reinforcing rods. The company needs to test a sample of the rods for breaking strength before the rods are installed. The site engineer selects a simple random sample of 49 of these reinforcing rods from the shipment and finds that the sample average breaking strength is 814 pounds. Assume that the standard deviation of the breaking strengths for the population of reinforcing rods in the shipment is known to be 35 pounds.
a. Construct a 95% confidence interval estimate of the average breaking strength you could expect to find if all the reinforcing rods in the shipment were tested.
b. Interpret the interval you constructed in part a.