Nilai; 50-60-70-80-90 Frek; 2-3-5-p-1 Jika mean 72, nilai P adalah

(50x2)+(60x3)+(70x5)+(80xp)+(90x1) = 72 x (2+3+5+p+1)
100+180+350+80p+90 = 72 x ( 11+p)
720 + 8p = 792 + 72p
80p - 72p = 792 - 720
8p = 72
p = 9