The breaking strengths of cables produced by a certain manufacturer have a standard deviation of 85 pounds. A random sample of 70 newly manufactured cables has a mean breaking strength of 1950 pounds. Based on this sample, find a 90% confidence interval for the true mean breaking strength of all cables produced by this manufacturer. Then give its lower limit and upper limit. Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place. (If necessary, consult a list of formulas.) Lower limit: X ? Upper limit