The yield point of a particular type of steel-reinforcing bar is known to be normally distributed 2. with an unknown and = 100.

The yield point of a particular type of steel-reinforcing bar is known to be normally distributed 2. with an unknown µ and σ = 100. Tests were conducted on a random sample of 64 bars, resulting in a sample average yield point of 8,000 lbs. Compute a 95% confidence interval for µ, the true average yield point of the bars.