Question

VERY IMPORTANT!! PLEASE HELPPP :(

Answer 1

Answer:

7

Step-by-step explanation:

Sigma notation means that you will add and continue adding using the function given.  Furthermore,  bottom number i = 1 is your starting point and the top number 3 is where you will stop the summation.  So,

Let i = 1:

$4(\frac{1}{2}^{1-1})=4(1)=4$

Let i = 2

$4(\frac{1}{2}^{2-1})=4(\frac{1}{2})=\frac{4}{2}=2$

Let i = 3

$4(\frac{1}{2}^{3-1})= 4((\frac{1}{2})^2 )=4\frac{1}{4}=\frac{4}{4}=1$

And so let's add up our results:

4+2+1=7