1) Determine if there is a linear relation among air temperature x1, wind speed x2, and wind child y. The following data show the measurement value for various days.
X1 -10 30 0 -30 20 0 30 30 -20 -30 -30 -20 10 -10
X2 50 30 10 100 90 40 20 50 30 50 70 40 80 20
Y -62 0 -22 -104 -32 -44 6 -8 -64 - 88 -98 -70 -44 -44
(a) Find the least squares regression equation Y= b0 + b1x1 + b2x2, where x1 is air temperature and x2 is wind speed, and y is the respond variable, wind chill.
Y= (......) + (.......)x1 + (.......)x2 (Round to three decimal places as needed).
(b) Draw residual plots to assess the adequacy of the model. (Create a residual plot for air temperature and for wind speed).
What might you conclude based on the plot of residuals against wind speed.