Three methods to compute mean for grouped data: (1) Direct: x-bar = sum(fixi)/N, best for small values. (2) Assumed Mean: x-bar = A + sum(fidi)/N where di = xi - A, reduces computation. (3) Step Deviation: x-bar = A + hsum(fiui)/N where ui = (xi-A)/h, most efficient for equidistant classes. All three give identical results — choice depends on computational convenience. For JEE, direct method or step deviation is typically fastest.