kak tolong di kerja kan semua ya dengan cara kerjanya

3) x = ( 2×4 ) + ( 4×5 ) + ( 5×6 ) + ( 3×7 ) + ( 3×8 ) + ( 2×9 ) + ( 1×10 ) / ( 2+4+5+3+3+2+1 )
x = ( 8+20+30+21+24+18+10 ) / 20
x = 131 / 20
x = 6,55
mean = 6,55
modus = nilai 6

4) x = { ( 11 × 7,5 ) + 9 } / 12
x = ( 82,5 + 9 ) / 12
x = 91,5 / 12
x = 7,625
rata2 = 7,6

5) a) modus = nilai 75
b) x = { (50 × 2 ) + ( 65 × 1) + ( 70 × 5) + ( 75 × 7) + (80 × 5) + ( 85 × 4) + ( 90 × 5) + ( 95 × 1 ) } / ( 2 + 1 + 5 + 7 + 5 + 4 + 5 + 1)
x = ( 100 + 65 + 350 + 525 + 400 + 340 + 450 + 95 ) / 30
x = 2325 / 30
x = 77,5
rata2 = 77,5