=+13.25 ● ▼ 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