3) Construct a scatterplot of strength (y) versus diameter (x). Verify that a linear model is appropriate. b) Compute the least-squares line for predicting strength from diameter. () Compute the fitted value and the residual for each point. d) If the diameter is increased by 0.3 mm, by how much would you predict the strength to increase or decrease? e) Predict the strength for a diameter of 5.5 mm. Can the least-squares line be used to predict the strength for a diameter of 8 mm? If so, predict the strength. If not, explain why not. g) For what diameter would you predict a strength of 95 kN/mm? 9. Structural engineers use wireless sensor networks to monitor the condition of dams and bridges. The article "Statistical Analysis of Vibration Modes of a Suspension Bridge Using Spatially Dense Wireless Sensor Network" (S. Pakzad and G. Fenves, Journal of Structural Engineering, 2009:863-872) describes an experiment in which accelerometers were placed on the Golden Gate Bridge for the purpose of estimating vibration modes. For 18 vertical modes, the system was underdamped (damping ratio 1)? Explain why or why not. f) For what damping ratio would you predict a frequency of 2.0