Chapter 12, Problem 8RE

(a)

To determine

To calculate: Expected value $\text{E}(X)$ for the following table where $X$ is the total number of tests required.

$\begin{array}{ccc}\text{Test}\text{of}\text{Mixture}& & \\ & \text{Negative}& \text{Positive}\\ \text{Total}\text{tests}& 1& 6\\ \text{Probability}& 0.774& 0.226\end{array}$.

(b)

To determine

The number of tests the laboratory can run, if it uses the procedure described on 200 blood samples (that is, $40$ batches of $5$ samples).