The breaking strengths of cables produced by a certain manufacturer have a standard deviation of87

pounds. A random sample of70

newly manufactured cables has a mean breaking strength of1900

pounds. Based on this sample, find a90

%

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 alist of formulas.)

Lower limit:

Upper limit