Bill is due to retire in 10 years, at which time he will start collection pension benefits. His employer is scheduled to begin funding Bills pension benefits with the first annual payment due at the end of year 1 and the last annual payment at the end of year 10. The initial employers contribution is $1, 000 and will increase by %K per year. Employer contributions will earn interest at an annual effective interest rate of %5.

Bills employer can elect alternative funding: annual contributions made the exact same times, but these contributions begin at $500 and increase by $170 each year. Under this alternative funding, the employer contributions still earn an annual effective interest rate of %5.

Determine K < 5 so that both funding options have the same accumulated value at the end of year 10.