Exam 3: Finding Relationships Among Variables

To form a scatterplot of X versus Y,X and Y must be paired variables.

The correlation between two variables is a unitless and is always between -1 and +1.

We can infer that there is a strong relationship between two numerical variables when

The cutoff for defining a large correlation is

Displaying all correlations between 0.6 and 0.999 on a scatterplot as green and all correlations between -1.0 and -0.6 as red is known as

A scatterplot allows one to see

A line or curve superimposed on a scatterplot to quantify an apparent relationship is known as a(n)

The scatterplot is a graphical technique used to make apparent the relationship between two numerical variables.

A trend line on a scatterplot is a line or a curve that "fits" the scatter as well as possible.

The limitation of covariance as a descriptive measure of association is that it

Scatterplots are also referred to as

An example of a joint category of two variables is the count of all non-drinkers who are also nonsmokers.

Correlation and covariance measure

We do not even try to interpret correlations numerically except possibly to check whether they are positive or negative.

To examine relationships between two categorical variables,we can use

Statisticians often refer to the pivot tables that display counts as contingency tables or crosstabs.

Correlation and covariance can be used to examine relationships between numerical variables as well as for categorical variables that have been coded numerically.

We must specify appropriate bins for side-by-side histograms in order to make fair comparisons of distributions by category.

The tool that provides useful information about a data set by breaking it down into categories is the

The tables of counts that result from pivot tables are often called