Ainda com base nas informações do texto, a variância do est...
![](https://qcon-assets-production.s3.amazonaws.com/images/provas/95971/Captura_de%20Tela%20%282046%29.png)
W1 = 2000/5000 = 2/5
W2 = 3000/5000 = 3/5
S1^2 = 8^2 = 64
S2^2 = 7^2 = 49
n1 = 200
n2 = 300
V(média) = (2/5)^2 * 64/200 + (3/5)^2 * 49/300 = 0,0512 + 0,0588 = 0,11
W1 = 2000/5000 = 2/5
W2 = 3000/5000 = 3/5
S1^2 = 8^2 = 64
S2^2 = 7^2 = 49
n1 = 200
n2 = 300
V(média) = (2/5)^2 * 64/200 + (3/5)^2 * 49/300 = 0,0512 + 0,0588 = 0,11