Question

Preciso dessa resposta urgente

Answer 1

Média ponderada:

8 = ((7 × 1 ) + (8 × 2) + (9 × 3) + (x × 4))/(1+2+3+4)

8= (7 + 16 + 27 + 4x)/10

8 × 10 = 50 + 4x

80 - 50 = 4x

x =30/4

x= 7,5