The mathematical equation relating the independent variable to the expected value of the dependent variable; that is, E(y) = b0 + b1x, is known as the? estimated regression equation. correlation model. regression equation. regression model.

Demand for Candy Bars In this problem you will determine a linear demand equation that describes the demand for candy bars in your class. Survey your classmates to determine what price they would be willing to pay for a candy bar. Your survey form might look like the sample to the left. a Make a table of the number of respondents who answered yes at each price level. b Make a scatter plot of your data. c Find and graph the regression line y=mp+b, which gives the number of respondents y who would buy a candy bar if the price were p cents. This is the demand equation. Why is the slope m negative? d What is the p-intercept of the demand equation? What does this intercept tell you about pricing candy bars? Would you buy a candy bar from the vending machine in the hallway if the price is as indicated. Price Yes or No 50 75 1.00 1.25 1.50 1.75 2.00

HOW DO YOU SEE IT? Discuss how well a linear model approximates the data shown in each scatter plot.

Cellular Phone Subscribers The table shows the numbers of cellular phone subscribers y in millions in the United States from 2008 through 2013. Source: CTIA- The Wireless Association Year200820092010201120122013Number,y270286296316326336 (a) Find the least squares regression line for the data. Let x represent the year, with x=8 corresponding to 2008. (b) Use the linear regression capabilities of a graphing utility to find a linear model for the data. How does this model compare with the model obtained in part a? (c) Use the linear model to create a table of estimated values for y. Compare the estimated values with the actual data.

What is extrapolation when using a linear model?

Does the following table represent a linear function ? If so, find the linear equation that models the data.

What is regression analysis? Describe the process of performing regression analysis on a graphing utility.

Sales Barnes & Noble had annual sales of $6.8 billion in 2013 and $6.1 billion in 2015. Use the Midpoint Formula to estimate the sales in 2014. Assume that the annual sales followed a linear pattern.

3.4 SKILL BUILDING EXERCISES Getting Regression Lines Only Find the equation of the regression line for the following data set. x 1 2 3 y 3 3 4

3.4 SKILL BUILDING EXERCISES Getting Regression Lines For the following data: a Plot the data. b Find the equation of the regression line. c Add the graph of the regression line to the plot of the data points. x 1.3 2.5 3.3 4.2 5.1 y 2.6 2.6 2 1.8 1.5