Answer:
(2) it decreases by 22% per year
Step-by-step explanation:
The value of the portfolio is described by the expression

where
30,000 is the value of the initial portfolio
x is the number of years
0.78 is the rate of change of the portfolio
To answer the question, we evaluate the value of the portfolio after one year, that is when
x = 1
Substituting into v(x), we find:

So, the loss in value of the portfolio in one year is:

And so, the loss percentage in the portfolio is:

So the correct answer is
(2) it decreases by 22% per year