Question

The breaking strengths of cables produced by a certain manufacturer have a standard deviation of 91 pounds. A random sample of 80 newly manufactured cables has a mean breaking strength of 1750 pounds. Based on this sample, find a 95% confidence interval for the true mean breaking strength of all cables produced by this manufacturer. Then complete the table below.

Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place. 

(If necessary, consult a list of formulas.)

I need both the lower limit, and upper limit of the 90% confidence interval.