1. Section 2-5 Continued Scatter Plots And Correlation

2. Def: A scatter plot shows the relationship between a collection of ordered pairs. Enter your lists of data Steps on Calculator Stat then Enter (you will see lists) Enter data by entering x-values in L 1 and y-values in L 2 To clear data Steps on Calculator y = clear all equations Stat then Edit ( you will see lists) move curser to L 1 Clear move curser to L 2 Clear To make a scatter plot using your calculator use the following steps:

3. 1. Enter this table into your calculator and make a plot. Where h = hours studied (x) s = test score (y) List 1List 2

4. To make the plot Steps on Calculator 2nd Stat Plot (select Plot 1) by keying Enter (you will now see the menu for making a plot) Move curser over the desired menu selections below and key enter after each choice On Off Type (first choice) X List (select L 1 or enter list name) Y List (select L 2 or enter list name) Mark (first choice)

5. To graph Steps on Calculator 2nd Quit (returns you to the main screen) Window adjust window to fit the data (key Enter after each entry) Xmin= -10 Xmax= 100 Xscl= 1 Ymin= -10 Ymax= 120 Yscl= 1 Now key GRAPH

6. 2. Find the line of “best fit” The calculator steps are: STAT CALC 4:LinReg(ax+b)Enter,,, Your home screen will say:LinReg (ax + b) Enter

7. The calculator will calculate the answer: y = ax + b Where b = y-intercept a = slope a = 5.643791 b = 57.90359 Line of best fit y = (5.643791)x + 57.90359

8. 3. Enter the equation of best fit into your calculator y = (5.643791)x + 57.90359 Does the line look like a reasonable approximation of the data? Def: The process your calculator goes through To find the line of best-fit is called a regression analysis

9. Homework Page102 # 1,2 and 3 Use you calculator to draw a scatter plot Use your graphing calculator to find the equation for line of best-fit (write the equation in y= mx +b form on your homework). Answer analysis questions