tolong dijawab no 15 dandikasih jalan ya

Mean = rata rata

jumlah data
__________
banyak data

=4×7+9×5+12×5
_____________
5+5+7

=28+45+60
_________
17

=133
____
17

=7 14/17

Semoga bermanfaat :)

Mean = jmlh data : banyak data
Mean = ( 4.7 + 9.5 + 12.5) : (7+5+5)
Mean = (28 + 45 + 60) : (17)
Mean = 133 : 17 = 7 14/17