Introduction to two-way tables copy (real one)

How many columns does a 5x3 table have?

3

How many rows does a 4x7 table have

4

what is simpson's paradox

A situation where the relationship between two variables is in one direction when a third lurking variable is included, but in the opposite direction when the third lurking variable is ignored. Simpson's paradox occurs when the relationship between two variables reverses with the inclusion of a third lurking variable.

Which of the following might be an example of Simpson's paradox?

Percentage of accident victims who die while being flown to the hospital in a helicopter exceeding the percentage of accident victims who die while being driven to the hospital in an ambulance. Accident victims are not flown to the hospital in a helicopter unless their condition is very serious. So accident victims who are flown to the hospital in a helicopter are more likely to die due to their condition than accident victims who are driven to the hospital in an ambulance. The other two examples do not have an obvious lurking variable.

When should you suspect Simpson's paradox?

Whenever the relationship between two variables differs from what you expect it to be.

How do we display the resulting counts when two categorical measurements are taken on each individual? (i.e., How should we display bivariate categorical data?)

With a two-way table

Which of the following operations is valid for categorical data?

counting

True or false: A marginal distribution for rows is created using the row totals in the numerators and the table total as the denominator for each percentage.

true

True or false: The numbers given in a two-way table are counts.

true

True or false: The sum of the row totals always equals the sum of the column totals.

true