The goals of this note are to derive formulas for the coefficients a and b in the least-squares regression plane y = at + bx + c for observations (t[subscript]i,x[subscript]i,y[subscript]i), i = 1, 2, ..., n, and to present meanings for the coefficients a and b. In this note, formulas for the coefficients a and b in the least-squares fit are derived using neither calculus nor matrices and the meanings of a and b are explored. Coefficients of partial correlation emerge naturally in the derivation. (Contains 1 figure.)