The article “Effect of Temperature on the pH of Skim Milk” (Journal of Dairy Research [1988]:

277– 280) reported on a study involving x 5 temperature

(8C) under specified experimental conditions and y 5 milk pH. The accompanying data (read from a graph) are a representative subset of that which appeared in the article:
x 4 4 24 24 25 38 38 40 y 6.85 6.79 6.63 6.65 6.72 6.62 6.57 6.52 x 45 50 55 56 60 67 70 78 y 6.50 6.48 6.42 6.41 6.38 6.34 6.32 6.34 a x 5 678 a y 5 104.54 a x2 5 36,056 a y2 5 683.4470 a xy 5 4376.36 Do these data strongly suggest that there is a negative linear relationship between temperature and pH? State and test the relevant hypotheses using a significance level of .01.