Polyester fiber ropes are increasingly being used as componentsof mooring lines for

Chapter 13, Problem 16

(choose chapter or problem)

Polyester fiber ropes are increasingly being used as componentsof mooring lines for offshore structures in deepwater. The authors of the paper Quantifying theResidual Creep Life of Polyester Mooring Ropes (Intl.J. of Offshore and Polar Exploration, 2005: 223228)used the accompanying data as a basis for studying howtime to failure (hr) depended on load (% of breaking load):x 77.7 77.8 77.9 77.8 85.5 85.5y 5.067 552.056 127.809 7.611 .124 .077x 89.2 89.3 73.1 85.5 89.2 85.5y .008 .013 49.439 .503 .362 9.930x 89.2 85.5 89.2 82.3 82.0 82.3y .677 5.322 .289 53.079 7.625 155.299A linear regression of log(time) versus load was fit. Theinvestigators were particularly interested in estimatingthe slope of the true regression line relating these variables.Investigate the quality of the fit, estimate the slope,and predict time to failure when load is 80, in a way thatconveys information about reliability and precision.