A windmill is used to generate direct current. Data are collected on 45 different days to determine the relationship between wind speed in mi/h (x) and current in kA (y). The data are presented in the following table.

a. Compute the least-squares line for predicting y from x. Make a plot of residuals versus fitted values.

b. Compute the least-squares line for predicting y from ln x. Make a plot of residuals versus fitted values.

c. Compute the least-squares line for predicting ln y from x. Make a plot of residuals versus fitted values.

Wind Wind Wind Speed Speed Speed Day Current Day Current Day Current 4.2 1.4 3.7 5.9 2.1 1.9 16 31 2.6 1.4 7.7 2.8 0.7 17 2.2 32 3 6.6 2.2 18 6.0 2.6 33 6.1 2.4 4 4.7 2.0 19 10.7 3.2 34 5.5 2.2 35 5.3 2.6 1.1 20 2.3 4.7 2.3 5.8 36 37 6. 2.6 21 5.1 1.9 4.0 2.0 1.8 0.3 22 4.9 2.3 2.3 1.2 11.9 5.8 2.3 23 8.3 3.1 38 3.0 9. 7.3 2.6 24 7.1 2.3 39 8.6 2.5 7.1 10 2.7 25 9.2 2.9 40 5.6 2.1 11 6.4 2.4 26 4.4 1.8 41 4.2 1.7 12 2.2 2.6 4.6 1.6 27 28 8.0 10.5 42 43 6.2 7.7 2.3 2.6 13 1.1 3.0 14 2.3 1.5 29 5.1 2.1 44 6.6 2.9 4.2 2.5 15 1.5 30 5.8 45 6.9 2.6