Answer:
The annual increase in the value of the certificate would have been 6.22 percent
Explanation:
From the provided data we have,
Worth of the silver certificate in 1898 equal to $10
Price sold for the silver certificate in 2015 equal to $11,700
To determine what would the annual increase in the value of the certificate have been;
Price sold = original price × (1 + r)( initial year bought - year sold)
$11,700 = $10 ×(1 + r)(2015- 1898)
r = 6.22 percent