Discuss the Applications of Confidence Interval Estimation
Use the Table

Discuss the applications of confidence interval estimation
Use the table below to answer the following question(s) .
The historical data of Velvetta Inc., a healthcare products manufacturer, have shown that in a production process for filling bottles of shampoo, variance in the volume is constant; however, clogs in the filling machine often affect the mean volume. The historical standard deviation is 5 milliliters. In filling 250-milliliter bottles, a sample of 20 found a meanvolume of 242 milliliters. $$\begin{array} { | l | l | } \hline \text { Velvetta Inc. Shamp o0 } & \\\text { Production } & \\\hline \text { Alpha Vahe } & 0.05 \\\hline \text { Standard Deviation } & 5 \\\hline \text { Sample Size } & 20 \\\hline \text { Sample Mean } & 242 \\\hline\end{array}$$
-In which of the following cases is a proportion of the observations of a sample used in estimating the confidence interval?

A) when the degrees of freedom are too large
B) when a true sampling distribution cannot be estimated
C) when the population standard deviation is known
D) when variables have only two possible outcomes