Use a least squares approximation to find the best linear fit (i. e., the best line), l(t)=c+dt, l(t)=c+dt, that is closest, in the sense of least squares, to passing through the through the following data points: (t1,b1)=(−3,28)(t1,b1)=(−3,28) ,, (t2,b2)=(0,7)(t2,b2)=(0,7) ,, (t3,b3)=(3,−20)(t3,b3)=(3,−20) ,, (t4,b4)=(6,−43)(t4,b4)=(6,−43) .. what are the yy-intercept cc and the slope dd of this line?