Salazar needs to save 100,000 over the next 10 years. He earns a nominal rate of interest of 7.2%, compounded monthly. Salazar mistakenly believes he can accumulate this amount by making monthly payments of 545, starting one month from today. He discovers his error at the end of 7 years. He decides to make up the difference by making payments of 545 + k for the remaining 3 years. Calculate k