Answer:
90
Step-by-step explanation:
To find s4 we find sum of values when n=1,n=2,n=3,n=4
given expression is ![6(2)^{n-1}](https://tex.z-dn.net/?f=6%282%29%5E%7Bn-1%7D)
n=1 , plug in 1 for n
![6(2)^{1-1}=6](https://tex.z-dn.net/?f=6%282%29%5E%7B1-1%7D%3D6)
n=2
![6(2)^{2-1}=12](https://tex.z-dn.net/?f=6%282%29%5E%7B2-1%7D%3D12)
n=3
![6(2)^{3-1}=24](https://tex.z-dn.net/?f=6%282%29%5E%7B3-1%7D%3D24)
n=4
![6(2)^{4-1}=48](https://tex.z-dn.net/?f=6%282%29%5E%7B4-1%7D%3D48)
Sum of all 4 terms = 6+12+24+48=90
I did not catch well, but i think you already got your answers. Let me explain. For the first part you got your notation right: for 0.0045 the correct scientific notation is 4.5 x 10^-3. Now the second part, the answer would be the first one, the notation that you are giving is the one who corresponds to <span>4.5 x 10^-2, the first option you have. Hope it helps</span>
This is an arithmetic series, so we know, that:
Sum = (First term + Last term) * Number of terms /2
Here we have:
First term = 33
Last term = 104
Number of terms = 104 - 33 + 1 = 72
and