1. Scatterplots AP Statistics CH. 7 EQ: How do we graph bivariate data?

2. Scatterplots Help to observe relationships between two quantitative variables(we call this describing bivariate data) Should have title, labels, units Can see patterns, trends, relationships, extraordinary values

3. Describing patterns Form-clusters, gaps, curved, linear, etc Strength-weak, strong, spread Direction(association)-positive or negative Unusual features-outliers, data far away from the rest

4. Response Variable (Dependent) Measures an outcome of a study In a scatterplot it goes on the y axis Explanatory/Predictor Variable (Independent) -Attempts to explain the observed outcome -In a scatterplot it goes on the x axis

5. If there is a relationship, tell which is the explanatory and response variables. 1.The amount of time spent studying and the grade on the exam 2.The weight and height of a person. 3.The amount of yearly rainfall and the yield of a crop. 4.Maximum daily temperature and average monthly heating bills.

6. Principles Start with a graph Look for a pattern and deviations Add numerical descriptions Describe the overall pattern briefly

7. The high temperature in degree Fahrenheit and coffee sales (in hundreds of dollars) for a coffee shop for eight randomly selected days. TemperatureCoffee Sales 3226.2 3924.8 5119.7 6020 6513.3 7213.9 7811.4 8111.2

8. A.Tell which variable is explanatory and which is response. B.Graph the scatterplot. Describe it. C. Explain in a sentence what this says about high temperatures and coffee sales.

14. Book P. 164 # 2 Suppose you want to collect data for each pair of variables. You want to make a scatterplot. Which variable would be the explanatory variable and which would be the response variable? Discuss the likely direction, form, and strength. A. T-shirts at a store: price each, number sold B.Skin diving: depth, water pressure C.Skin diving: depth, visibility D.All elementary-school students: weight, score on a reading test

15. p.164 #2 ABCD VE: Price R: # Sold E: Depth R: Water pressure E: Depth R: Visibility E: Weight R: Reading DNegativePositiveNegativePositive UNone FLinear Linear (?)Possibly Linear SModerateStrongWeak to Moderate Moderate ABCD VE: R: E: R: E: R: E: R: D U F S

16. Book P. 164 # 6 Which scatterplot has a.Little or no association b.A negative association c.A linear association d.A moderately strong association e.A very strong association

17. HW P. 164 # 3, 5, 9, 11