Linear Regression and Correlation: Regression Lab II (edited: Teegarden) 1.1 2008/08/12 14:10:23.817 GMT-5 2008/08/12 14:11:06.964 GMT-5 Mary T Teegarden tteegard@sdccd.edu Mary T Teegarden tteegard@sdccd.edu elementary statistics This module provides a lab of Linear Regression and Correlation as a part of Collaborative Statistics collection (col10522) by Barbara Illowsky and Susan Dean. Labs changed to incorporate mini-tabs. Class Time: Name:

Student Learning Outcomes: The student will calculate and construct the line of best fit between two variables. The student will evaluate the relationship between two variables to determine if that relationship is significant.

Collect the DataSurvey 10 textbooks. Collect bivariate data (number of pages in a textbook, the cost of the textbook). Complete the table.

Number of pages Cost of textbook

Which variable should be the dependent variable and which should be the independent variable? Why? Graph “number of pages” vs. “cost.” Plot the points on the graph. Label both axes with words. Scale both axes.

Does there appear to be a relationship between the size of the book and it's cost?

Analyze the DataEnter your data into your MiniTab. Record the following information. correlation coefficient = ___________ p-value = ___________ Is three significant correlation to use a regression line? Calculate the following: a a = b b = c n = d equation: y = Obtain the graph using Minitab. Sketch the regression line below.

Supply an answer for the following senarios: aFor a textbook with 400 pages, predict the cost: b For a textbook with 600 pages, predict the cost:

Discussion QuestionsAnswer each with 1-3 complete sentences. aDoes the line seem to fit the data? Why? bWhat does the correlation imply about the relationship between the number of pages and the cost? Are there any outliers? If so, which point(s) is an outlier? Should the outlier, if it exists, be removed? Why or why not?