a-qualitycontrol-engineer-is-interested-in-the-variability-of-caffeine-concentra

Question

A quality‐control engineer is interested in the variability of caffeine concentration (in $mg/mL$ ) in a particular brand of espresso. A simple random sample of $n equals 30$ cups is taken, and the sample standard deviation is found to be $s equals 0.35 mg slash mL$ . Assuming the population of concentrations is approximately normal, using a $95 percent sign$ confidence level, determine the degrees of freedom, the critical values $χ_{L}^{2}$ and $χ_{R}^{2}$ , and the confidence interval estimate (up to two decimal places) for the population standard deviation $σ$ .

Accepted Answer

$d f equals 29$

$chi sub L squared equals 16.047$

$chi sub R squared equals 45.722$

$95 percent sign$ CI: $0.28 mg slash mL is less than sigma is less than 0.47 mg slash mL$

Answer

$d f equals 29$

$chi sub L squared equals 16.047$

$chi sub R squared equals 45.722$

$95 percent sign$ CI: $0.28 mg slash mL is less than sigma is less than 0.47 mg slash mL$

Answer

$d f equals 29$

$chi sub L squared equals 16.047$

$chi sub R squared equals 45.722$

$95 percent sign$ CI: $0.28 mg slash mL is less than sigma is less than 0.47 mg slash mL$

Answer

$d f equals 29$

$chi sub L squared equals 16.791$

$chi sub R squared equals 46.979$

$95 percent sign$ CI: $χ_{R}^{2}$