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.