Example 3 A group of engineer wants to determine the stress level at which a wing component on an aircraft will fracture for a given fractured toughness. Table below shows the temperature and Impact Energy data tested on tempered steel alloy. Calculate the coefficient of correlation for the data. Then intepret the result. Temperature (C) 100 75 50 25 0 -25 -50 -65 -75 -85 -100 -125 -150 -175 Temperature(C).x 100 75 Example 4 A group of engineer wants to determine the stress level at which a wing component on an aircraft will fracture for a given fractured toughness. Table below shows the temperature and Impact Energy data tested on temperes steel alloy. Find the least square regression line for the following data. 50 25 0 -25 -50 -65 -75 Impact Energy (J) 89.3 88.6 87.6 -85 -100 -125 -150 -175 85.4 82.9 78.9 73.1 66.0 59.3 47.9 34.3 29.3 27.1 25.0 Impact Energy (J), y 89.3 88.6 87.6 85.4 82.9 78.9 73.1 66.0 59.3 47.9 34.3 29.3 27.1 25.0