please dont use excel, i need to see the math please

Problem 7 Maturity Zero-Coupon Yields 1 year 5.80% 2 years 6.10% 3 years 6.40% 4 years 6.70% 5 years 6.90% Figure 3: Zero-Coupon Yields Assume the zero-coupon yields on default-free securities are as summarized in the above table. What is the par coupon rate (in %) of a four-year, default-free security with annual coupon payments and face value of $1,000 issued at par