Presentation on theme: "10.1 Scatter Plots and Trend Lines"— Presentation transcript:
1 10.1 Scatter Plots and Trend Lines CCSS: S-ID Represent data on two quantitative variables on a scatter plot, and describe how the variables are related.Fit a function to the data; use functions fitted to data to solve problems in the context of the data. Use given functions or choose a function suggested by the context. Emphasize linear, quadratic, and exponential models
2 Essential Question: How can you describe the relationship between two variables and use it to make predictions?
3 Describing How Variables Are Related in Scatter Plots Two-variable data is a collection of paired variable valuesscatter plot: a graph of points with one variable plotted along each axis.Correlation is a measure of the strength and direction of the relationship between two variables.
7 Reflections What are the two variables? Are the variables correlated? Why are the points in a scatter plot not connected in the same way plots of linear equations are?
8 Answers 1. The 2 variables are Latitude and Temperature 2. The variables are negatively correlated.3. A straight line indicates a continuous set of points. Data in scatter plot are represented by discrete points. Line segments between points would incorrectly imply either data or function along segments between the scattered points.
9 Correlation Coefficient (r) – r close to r close to 1– r close to r close to 0.5
10 Example 1: Use a scatter plot to estimate the value of r Example 1: Use a scatter plot to estimate the value of r. lndicate whether r is closer to - 1, - 0.5, 0, 0.5, or l.
11 AnswerThis is strongly correlated and has a negative slope, so r is close to -1.
12 Ex. 2: This data represents the football scores from one week with winning score plotted versus losing score.The correlationcoefficient r is close to …
13 AssignmentUse a scatter plot to estimate the value of r. lndicate whether r is closer to - 1, - 0.5, 0, 0.5, or l