The paper “Effect of Temperature on the pH of Skim Milkâ€(Journal of Dairy Research) reported on a study involving x =temperature (degrees oC) under specified experimentalconditions and y = milk pH. The following data is a representativesubset of the data used in the study.
XÂ Â Â Â Â Â Â Â 14Â Â Â Â Â Â Â 18Â Â Â Â Â Â Â 23Â Â Â Â Â Â Â 24Â Â Â Â Â Â Â 26Â Â Â Â Â Â Â 38Â Â Â Â Â Â Â 38Â Â Â Â Â Â Â 40
YÂ Â Â Â Â Â Â Â 6.89Â Â Â Â 6.72Â Â Â Â 6.63Â Â Â Â 6.64Â Â Â Â 6.75Â Â Â Â 6.66Â Â Â Â 6.57Â Â Â Â 6.58
                                                                                              Â
XÂ Â Â Â Â Â Â Â 45Â Â Â Â Â Â Â 50Â Â Â Â Â Â Â 55Â Â Â Â Â Â Â 56Â Â Â Â Â Â Â 60Â Â Â Â Â Â Â 67Â Â Â Â Â Â Â 70Â Â Â Â Â Â Â 78
YÂ Â Â Â Â Â Â Â 6.59Â Â Â Â 6.48Â Â Â Â 6.42Â Â Â Â 6.41Â Â Â Â 6.38Â Â Â Â 6.34Â Â Â Â 6.32Â Â Â Â 6.34
a. Graph a scatter plot of X vs. Y. Does this data suggest alinear relationship between temperature and pH? Explain why or whynot.
b. Show the estimated linear regression line on the scatter plotin (1.).
c. Calculate the sample correlation between x and y. Would youconsider the correlation weak, moderate, or strong?
d. For a give temperature = 20 degrees oC, calculatethe estimated value of Y using the regression line equation
