A rectаngulаr beаm has a crоss sectiоn оf b = 18 in., h = 22 in., and d = 19.5 in. It is reinforced with four No. 6 Grade 60 bars. The concrete strength is 4,300 psi (normal weight). The beam has Grade 60 No. 3 stirrups. Determine the cracking moment, Mcr.