umur 21 22 23 24 25 freku 4 7 10 x 8 jika mean=23,125,nilai x adalah

mean= (21x4 + 22x7 + 23x10 + 24X + 25x8) / (4+7+10+x+8)

23,125= (84+154+230+24X+200) / 29
23,125x29 = 668+24X
670,625 = 668+24X
24X = 670,625-668
24X = 2,625
X= 2,625/24
X= 0,109

sorry kalau salah, semoga membantu :)