Please provide answer with formulas used . I am not looking for the answer as much as how it was calculated.

Suppose you own a condo at the beach that you can sell now for $166,347. If you wait 14 years and spend $45,158 to build a sea wall necessary to protect the property, you can sell your condo for $277,811. The interest rate on the loan to pay for the sea wall is 11%, and the $45,158 is borrowed at the end of year 2 and spent in a lump sum at that same time. The loan will accrue interest and be paid back at the end of the year in which the property is sold, as you do not have the ability to do so earlier without selling the property. The discount rate is assumed to be 7%. In present value terms, if you wait 14 years to sell the condo, and pay off the loan, by how much does your return exceed the value of selling it today for $166,347? (Round to the nearest dollar. If the selling today is worth more than waiting, use a negative sign on your answer.)

NOTE:To account for rounding, answers within $50 of the correct answer will be graded correct.That is, if the correct answer is $7,045.22, any answer within the 6,095.22 to 7,095.22 range will be correct.