Answer:
26
Explanation:
The increase per year is 6.5 which can be derived by subtracting the first year from the second year:
13-6.5=6.5
then subtracting the second year from the third to confirm
19.5-13=6.5
So now we know the increase all we do is add:
19.5+6.5=23
Method 2: A slightly more complicated method of solving is via a linear equation which in this scenario is Hⁿ=6.5N (the n means the nth term) and then we plug 4 into it to get Hⁿ=26