Rata rata dari data 63+72+56+90+50+63+94+61+88+x=75

637 + x = 75 x 10
637 + x =750
x = 750 -637
x = 113

rata" => 63+72+56+90+63+94+61+88+x=75
672+x/10=75/1
1x(672+x)=10(75)
672+x=750
x=750-672
x=78

maaf kalo salah...