Determine (a) the chi squaredχ2 test statistic, (b) the degrees of freedom, (c) the critical value using alpha equals 0.05α=0.05, and (d) test the hypothesis at the alpha equals 0.05α=0.05 level of significance. upper h 0h0: p subscript upper apaequals=p subscript upper bpbequals=p subscript upper cpcequals=p subscript upper dpdequals=one fourth14h1: outcome a b c dobserved 21 21 19 19expected 20 20 20 20at least one of the proportions is different from the others. how many degrees of freedom are therethe test statistic critical value