As the air temperature drops, river water becomes supercooledand ice crystals form. Such

Chapter 13, Problem 5

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As the air temperature drops, river water becomes supercooledand ice crystals form. Such ice can significantlyaffect the hydraulics of a river. The article LaboratoryStudy of Anchor Ice Growth (J. of Cold RegionsEngr., 2001: 6066) described an experiment in whichice thickness (mm) was studied as a function of elapsedtime (hr) under specified conditions. The following datawas read from a graph in the article: n 5 33;x 5 .17, .33, .50, .67,, 5.50; y 5 .50, 1.25, 1.50, 2.75,3.50, 4.75, 5.75, 5.60, 7.00, 8.00, 8.25, 9.50, 10.50,0xy0200400600800100012001400160020 40 60Load = 13.58 + 9.905 Discharge80Discharge (cfs)Load (Kg N/day)100 120SR-SqR-Sq (adj)69.010792.5%92.4%14011.00, 10.75, 12.50, 12.25, 13.25, 15.50, 15.00, 15.25,16.25, 17.25, 18.00, 18.25, 18.15, 20.25, 19.50, 20.00,20.50, 20.60, 20.50, 19.80.a. The r2 value resulting from a least squares fit is.977. Interpret this value and comment on theappropriateness of assuming an approximate linearrelationship.b. The residuals, listed in the same order as the x values,are21.03 20.92 21.35 20.78 20.68 20.11 0.2120.59 0.13 0.45 0.06 0.62 0.94 0.8020.14 0.93 0.04 0.36 1.92 0.78 0.35 0.67 1.02 1.09 0.66 20.09 1.33 20.1020.24 20.43 21.01 21.75 23.14Plot the residuals against elapsed time. What does theplot suggest?