2 Quantitative Variables - Scatterplots Flashcards
What graph do you use for 2 Quantitative variables?
A scatterplot.
What does a response (dependent) variable measure?
An outcome
What does an explanatory (indepdendent) variable explain?
An explanatory variable influences changes in the response variable.
The response variable is the event expected to change when the explanatory variable is manipulated.
Example: explanatory variable - hours of study per week. Response variable - final mark in STA 1003.
What are the axes for a scatterplot?
The explanatory variable is the X axis and the response variable is the Y axes.
What axies is the predicting variable on?
The variable we are predicting goes on the y-axis and is the depdent variable.
What is a High Leverage point?
A point that is unusual if its x-value is far from the mean of the x-values.
What is an influential point?
A point is influential if omitting it from the analysis changes the model enough to make a meaningful difference.
What is correlation?
How the variables in a scatterplot relate to each other OR how close a line is to all the points. (getting statistics from the scatterplot)
What is regression?
Regression is finding the ‘best’ straight line for the data. (fitting a model to the data)
What does Correlation measure?
Correlation measures the direction and strength of the linear relationship between two quantitative variables.
What is regression?
Regression finds the line on the scatterplot.
What is the main reason for finding a regression line?
The main reason is to make predictions.
What is a residual?
The residuals are how much the predictions miss by.
