Scatter Diagram of Bivariate Measurement Data. Bivariate Measurement Data Example of Bivariate...
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Scatter Diagram of Bivariate Measurement
Data
Bivariate Measurement Data
Example of Bivariate Measurement:
Some questions for Bivariate Data
• Are the variables related?• Can we quantify the strength of their relationship?• Can we predict one variable from the other?
• Let x, y be the two variables of a bivariate data.• The variable x is marked along the horizontal axis and y on the vertical
axis on a graph paper. • The pairs (x, y) of observations are then plotted as dots on the graph.• The resulting diagram is called a scatter diagram or scatter plot.
The correlation Coefficient
• If the scatter plot of (x,y) is a line, we say x and y has a linear relation. • The to measure how “linear” a relation is, we use the correlation
coefficient.
The correlation Coefficient, r
• The value of r is always between -1 and 1. • The magnitude of r indicates the strength of a linear relation, whereas
its sign indicates the direction.
Calculation r