An atomic absorption method for determination of copper in fuel samples yielded a pooled standard deviation of spooled 5 0.27 mg Cu/mL (s S s). The analysis of an oil from a reciprocating aircraft...

Extracted text: An atomic absorption method for determination of copper in fuel samples yielded a pooled standard deviation of spooled 5 0.27 mg Cu/mL (s S s). The analysis of an oil from a reciprocating aircraft engine showed a copper content of 7.91 mg Cu/mL. Calculate the 95 and 99% confidence intervals for the result if it was based on (a) a single analysis, (b) the mean of 4 analyses, and (c) the mean of 16 analyses.