=+b. The residuals, listed in the same order as the x values, are 21.03 20.92 21.35 20.78 20.68 20.11 0.21 20.59 0.13 0.45 0.06 0.62 0.94 0.80 20.14 0.93 0.04 0.36 1.92 0.78 0.35 0.67 1.02 1.09 0.66 20.09 1.33 20.10 20.24 20.43 21.01 21.75 23.14 Plot the residuals against elapsed time. What does the plot suggest?