Bivariate Data & Scatter Plots
Bivariate data analysis investigates the relationship between two variables by plotting data on scatter plots and fitting lines or curves of best fit.
What You Need to Know
Key Concept Diagram
A scatter plot displays pairs of values for two variables, allowing visual identification of patterns and trends
Correlation describes the direction (positive/negative) and strength (strong/weak) of the linear relationship between two variables
A line of best fit (trend line) models the data and can be used to make predictions within or beyond the data range
Extrapolation (predicting outside the data range) is less reliable than interpolation (predicting within the data range)
Key Vocabulary
Bivariate data
Data that involves two variables collected from the same source (e.g., height and weight)
Correlation
A statistical measure of the strength and direction of the linear relationship between two variables
Line of best fit
A straight line drawn through a scatter plot that best represents the trend of the data
Outlier
A data point that lies far from the general pattern of the scatter plot
Knowledge Check
Select the correct answer for each question. Click "Check Answer" to see if you are right.
Question 1
A scatter plot shows that as study hours increase, test scores also increase. What type of correlation is this?
Question 2
Which of the following best describes interpolation?
Question 3
A line of best fit passes through (0, 5) and (10, 25). What is the equation of this line?
Key Concepts Summary
- ●A scatter plot displays pairs of values for two variables, allowing visual identification of patterns and trends
- ●Correlation describes the direction (positive/negative) and strength (strong/weak) of the linear relationship between two variables
- ●A line of best fit (trend line) models the data and can be used to make predictions within or beyond the data range
- ●Extrapolation (predicting outside the data range) is less reliable than interpolation (predicting within the data range)