nilai.5,6,7,8,9. frekuensi 3,5,1,x,4 .rata rata tabel d atas adalah 7,0 nilai x adalah

7,0 = { ( 3 × 5 ) + ( 5 × 6 ) + ( 1 × 7 ) + ( x × 8 ) + ( 4 × 9 ) } / ( 3 + 5 + 1 + X + 4 )

7,0 = ( 15 + 30 + 7 + 8x + 36 ) / ( 13 + x )

7,0 ( 13 + x ) = 88 + 8x

91 + 7x = 88 + 8x

91 - 88 = 8x - 7x

x = 3