Presentation on theme: "1.6 Scatter Plots and Lines of Best Fit"— Presentation transcript:
1 1.6 Scatter Plots and Lines of Best Fit Objectives: Interpret data in a scatter plot. Find a line of best fit on a scatter plot by inspection.Standard Addressed: C: Fit a line to a scatter plot of two quantities and describe any correlation of the variables.
2 Scatter plots provide a picture of the relationship between two sets of data. Scatter plots and lines of best fit can be used to predict relationships and future occurrences.A scatter plot shows how 2 variables relate to each other by showing how closely the data points cluster to a line. Scatter plots provide a convenient way to determine whether a relationship exists between 2 variables.The relationship is called a correlation.A positive correlation occurs when both variables increase.A negative correlation occurs when one variable increases and the other variable decreases.
4 Ex. 2 Think of 2 examples of related data Ex. 2 Think of 2 examples of related data. Describe the kind of correlation you expect from the data and why.Age color vs. Hair No CorrelationAge Car vs. Value $ Negative CorrelationStudy vs. Grade Positive Correlation
5 Finding Lines of Best Fit Scatter plots can be used to show trends in data. When the points in a scatter plot are represented by a trend line or line of best fit, you can study the line to see how the data behave. You may have a basis to predict what the data might be for values not given.
6 Ex. 3 Calculator and Years!! Y = 15.9x -371.8 195019551960196519701975198019851990# of storms2006006209006509208807001180Y = 15.9xR = .80 Moderate Positive Correlation