Answer
$-\frac{5}{16}$
Work Step by Step
Given i = 1 to 4
Then the sum = $(-\frac{1}{2})^{1}$ + $(-\frac{1}{2})^{2}$ + $(-\frac{1}{2})^{3}$ + $(-\frac{1}{2})^{4}$
= $ (-\frac{1}{2})$ + $ (\frac{1}{4})$ + $ (-\frac{1}{8})$ + $ (\frac{1}{16})$
= $\frac{(-8 + 4 - 2 +1)}{16}$
= $-\frac{5}{16}$
