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Jen buys a 10-year bond of face (and redemption) amount of $1000, with 10% annual coupons at a price to yield an annual effective rate of 10%. The coupons are immediately reinvested at an annual effective rate of 8% once received.

Immediately after receiving and reinvesting the 4th coupon, Jen sells the bond to Lee for a price that will yield an annual effective rate of 12% to Lee. Calculate the yield rate that Jen actually earns on her investment.