Contingency Tables · Exercise 14

Use the information in the to answer the next eight exercises. The table shows the political party affiliation of each of 67 members of the U.S. Senate in June 2012, and when they would next be up for reelection.
$$\begin{array}{ccccc}\text{Up for Reelection:}& \text{Democratic Party}& \text{Republican Party}& \text{Other}& \text{Total}\\ \text{November 2014}& \text{20}& \text{13}& \text{0}& \\ \text{November 2016}& \text{10}& \text{24}& \text{0}& \\ \text{Total}& & & & \end{array}$$

What is the probability that a randomly selected senator was a Democrat and was up for reelection in November 2016?

OpenStax, Statistics · §3.4 Contingency Tables · Exercise 14