# Question: A random sample of n 40 pipe sections resulted in

A random sample of n= 40 pipe sections resulted in a mean wall thickness of 0.1264 in. and a standard deviation of 0.0003 in. We assume that wall thickness is normally distributed.

(a) Between what limits can we say with 95% confidence that 95% of the wall thicknesses should fall?

(b) Construct a 95% confidence interval on the true mean thickness. Explain the difference between this interval and the one constructed in part (a).

(a) Between what limits can we say with 95% confidence that 95% of the wall thicknesses should fall?

(b) Construct a 95% confidence interval on the true mean thickness. Explain the difference between this interval and the one constructed in part (a).

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