Probability & Statistics Contingency Tables

Contingency Tables T. Serino To study contingency tables, we will revisit the Titanic example. Recall the following frequency table of Titanic passengers. Total 2201

Contingency Tables Children and first class passengers first? T. Serino Children and first class passengers first?

Contingency Tables T. Serino The following is a contingency table of ticket Class and Survival. The bottom line of the “Totals” is the same as the previous frequency table.

Contingency Tables T. Serino To describe a contingency table with percent becomes a bit more challenging than when we converted a frequency table to a relative frequency table. The big question becomes, “Percent of what?”

T. Serino Contingency Tables

Contingency Tables “the part is a percent of the whole” T. Serino When calculating percent, we start with a fraction, change to a decimal, then rewrite as a percent. To help with this, try to remember that “the part is a percent of the whole” In the English sentence, “the whole” always comes after the words, “percent of”

Contingency Tables Example1: T. Serino Example1: What percent of second class passengers survived? The part is second class passengers who survived. The whole is all second class passengers.

Contingency Tables Example 2: T. Serino Example 2: What percent of passengers were second class survivors? The part is second class passengers who survived. The whole is all passengers.

Contingency Tables Example 3: T. Serino Example 3: What percent of survivors were second class passengers? The part is second class passengers who survived. The whole is all survivors.

Contingency Tables Try this: T. Serino Try this: 1.) What percent of third class passengers died? 2.) What percent of survivors were first class passengers? 3.) What percent of passengers were crew members?

athematical M D ecision aking