(e) The following is a graph of > versus the corresponding observed values yj. Scatterplot of fitted vs WOD 45 . 35 Fitbed 25- 20- 1-0 LA I.E 20 25 31 Which of the following describes what this plot would look like if the relationship between y and xwas a deterministic (no random error) straight line? O the points would be in a completely random pattern O the points would all be equal O the points would fall on a horizontal line O the points would fall along a 450 line (f) Does the plot actually obtained indicate that time is an effective regressor variable in predicting BOD?An article in the Journal of the Environmental Engineering Division ("Least Squares Estimates of BOD Parameters," Vol. 106, 1980, pp. 1197-1202) describes the results of testing a sample from the Holston River below Kingport, TN, during August 1977. The biochemical oxygen demand (BOD) test is conducted over a period of time in days. The resulting date is shown below: Time (days) |BOD (me/liter) 1 0.6 2 0.7 4 15 6 19 8 2.1 10 2.6 12 2.9 14 3.7 16 3.5 18 3.7 20 3.8 Minitab output resulting from fitting a simple linear regression model with time as the explanatory variable and BOD as the response follows. Predictor Coef SE Coef T Constant 0.6578 0.1657 3.97 0.003 Time 0.17806 0.01400 12.72 0.000 5 = 0.287281 R-Sq = 94.7% R-Sq(adj) = 94.1% Analysis of Variance Source DE MS Regression 1 13.344 13.344 161.69 0.000 Residual 0.743 0.083 Error Total 10 14.087