Section 10 Lab Intro to SLR

STAT 3090 S ECTION 10 L AB S PRING 2023 I NTRODUCTION TO LSRL N AME : Josh Hartke O BJECTIVES : Upon completion of this lab, you should be able to:  Complete a least squares regression line for a given data set on JMP  Determine the independent/dependent variables  Interpret the value for the slope  Interpret the value for the y-intercept if appropriate  Calculate residuals using given data and calculated data It is a fun fact that you can calculate the temperature based on the frequency of cricket chirping. This is sometimes called Dolbears law, as a formula for temperature based on the number of times crickets chirp in 15 seconds was published by Amos Dolbear in 1897. The formula states that the temperature in degrees Fahrenheit should be equal to the number of times crickets chirp in 15 seconds plus 40 degrees. In this assignment we want to see if this is true, and find the formula for ourselves. In the JMP file “Dolbear’s_Law.JMP” we have various recordings of cricket chirps and temperature, provided in the GLOBE article that can be found here ( https://www.globe.gov/explore-science/scientists-blog/archived- posts/sciblog/index.html_p=45.html ). D IRECTIONS : Answer the following questions using complete sentences as though you were presenting your analysis to an academic journal where Dolbear’s law is researched. Please provide any appropriate output and/or screenshots from JMP. Instructions for creating several types of graphs or tables and statistics can be found on Canvas in the file JMP Instructions.docx . Paste your answers and any output into this document. We will find the LSRL for cricket chirps per 15 seconds and temperature in Fahrenheit. 1. Which is the dependent variable? Explain your choice. (10 points) The temperature is the dependent variable in the problem because it depends on the amount of cricket chirps per 15 seconds. 2. Which is the independent variable? Explain your choice. (10 points) 1

STAT 3090 S ECTION 10 L AB S PRING 2023 I NTRODUCTION TO LSRL The independent variable is the amount of cricket chirps per 15 seconds because this is what is measured and defines the temperature. 3. Use JMP to plot temperature vs cricket chirps per 15 seconds and find the LSRL for the data. Post the results below, be sure to include the plot with the LSRL and the equation for the LSRL. (10 points) LSRL = -42.0005 + 1.0775x 4. Which value estimates β 0 ? Use the appropriate symbol for the estimate and include units. Is this the y-intercept or the slope? (10 points) = -42.0005 and y intercept 5. Interpret the y-intercept in this problem if appropriate (10 points) There is not a valid interpretation of the y intercept for this problem 2