Answer:
The current value of the stamp collection is of $2,191.
Explanation:
Compound interest:
The compound interest formula is given by:

Where A(t) is the amount of money after t years, P is the principal(the initial sum of money), r is the interest rate(as a decimal value), n is the number of times that interest is compounded per year and t is the time in years for which the money is invested or borrowed.
A stamp collection is purchased for $1,000.
This means that

The rate of return on the stamp collection is 4% per year
This means that

So



What is the current value of the stamp collection?
This is A(20). So

The current value of the stamp collection is of $2,191.