Wednesday Today you need: Whiteboard, Marker, Eraser Calculator 1 page handout

Warm-up Need a White Board 1. Graph the following equation:

Warm-up Need a White Board 1. Graph the following equation:

Linear Regression Section 2-6 Pages

Objectives I can use Linear Regression with a calculator to find linear prediction Equations I can find the correlation co-efficient “r” for the data

Correlation Co-efficient The correlation co-efficient “r” tells how linear the data is. Values of 1 or –1 indicate perfect linear lines, either positive or negative Values closer to zero mean the data has no linear relationship Small whiteboard number line with r=1 and r=-1

Sample “r Values

Plotting Data When the data you plot forms a near linear relationship, then we can use a linear equation to approximate the graph. We use what’s called a Best-Fit Line. This line is drawn to be as close to the data points as possible, but may not touch them all.

Weeks Experience Speed (wpm) x-axis y-axis 0

Using the Calculator (Linear Regression) The calculator is a great resource to give us a prediction equation. It is more accurate than doing the equation Manually We will enter the data into the STAT mode of the calculator

Linear Regressions on the calculator: Turn Diagnostics On. 2nd catalog, arrow to Diagnostic on, enter, enter (you should clear the calculator before beginning) 2 nd, +, 7, 1, 2 #1.

Linear Regression Finding the equation of your “Best Fit Line” STAT, then EDIT Enter X-Values in L1, Y-Values in L2 STAT, then CALC Choose (4) LIN REG

Weeks Experience Speed (wpm) x-axis y-axis 0

The table below shows the years of experience for eight technicians at Lewis Techomatic and the hourly rate of pay each technician earns. Experience in years Hourly rate of Pay in dollars

Prediction Equations y = 1.234x Remember: x = Experience in Years y = Pay rate in dollars We can use this to predict other values

Predictions: 25 years experience

Predictions: $32.72 per hour

When Dealing with Years Must modify years starting at “0” If you don’t you get a really negative y- intercept value that won’t match the graph Example on next slide

Inputting Years If the Independent variable is Years and these are your values Then these are the values we will actually enter for L

Homework Linear Regression Ws