Answer:
80
Explanation:
The variable "n" is not defined, but rather "k" is used in the summation. Assuming that "n" was meant to be "k", the expression should be:
s4 = ∑ k=1 to 4 of 2(3^(k-1))
To evaluate this expression, we need to substitute each value of k from 1 to 4 into the expression 2(3^(k-1)), and then sum up the results.
Starting with k = 1:
2(3^(1-1)) = 2(3^0) = 2(1) = 2
Moving on to k = 2:
2(3^(2-1)) = 2(3^1) = 2(3) = 6
Next, k = 3:
2(3^(3-1)) = 2(3^2) = 2(9) = 18
Finally, k = 4:
2(3^(4-1)) = 2(3^3) = 2(27) = 54
Now we add up these four results:
s4 = 2 + 6 + 18 + 54 = 80
Therefore, the value of s4 is 80.