An engineer borrowed $3000 from the bank, payable in six equal end-of-year payments at 8%. The bank agreed to reduce the interest on the loan if interest rates declined in the United States before the loan was fully repaid. At the end of 3 years, at the time of the third payment, the bank agreed to reduce the interest rate on the remaining debt from 8% to 7%. What was the amount of the equal end-of-year payments for each of the first 3 years? What was the amount of the equal annual end-of-year payments for each of the last 3 years? (Answer: $648.90 and $637.28) *****( Please show step by step works specially 2nd part & thanks)