Question

Calcule o valor numérico da soma sabendo que:
X1=2, X2=6, X3=7, X4=9
Y1=1, Y2=4, Y3=5, Y4=11
​

Answer 1

$\sum_{i=2}^4 \sum_{j=2}^3 3 \cdot (X_{i} - Y_{j}) = \\3 \cdot \left[(X_2-Y_2) + (X_2 - Y_3) + (X_3 - Y_2) + \\(X_3 - Y_3) + (X_4 - Y_2) + (X_4 - Y_3) \right]$

Substituindo os valores:

$\sum_{i=2}^4 \sum_{j=2}^3 3 \cdot (X_{i} - Y_{j}) = 3 \cdot \left[(6-4) + (6 - 5) + (7 - 4) + (7 - 5) + (9 - 4) + (9 - 5) \right]$

$\sum_{i=2}^4 \sum_{j=2}^3 3 \cdot (X_{i} - Y_{j}) = 3 \cdot \left[2 + 1 + 3 + 2 + 5 + 4 \right]$

$\sum_{i=2}^4 \sum_{j=2}^3 3 \cdot (X_{i} - Y_{j}) = 3 \cdot 17$

$\sum_{i=2}^4 \sum_{j=2}^3 3 \cdot (X_{i} - Y_{j}) = 51$