=+34. The accompanying data was extracted from the article “Effects of Cold and Warm Temperatures on Springback of Aluminum-Magnesium Alloy 5083-H111” (J. Engr. Manuf., 2009: 427–431). The response variable is yield strength (MPa), and the predictor is temperature ( C).

x: 250 25 100 200 300 y: 91.0 120.5 136.0 133.1 120.8 Here is Minitab output from fitting the quadratic