You were asked to calculate the convexity of a 10 year bond that has a coupon of 2.80% and a YTM of 3.40%. You could have typed the numbers into the duration calculator rather than actually multiplying the pvs by time and t+1. To ensure you did the work, please answer this question: For the 11th coupon, what is the present value times t times t+1? (The answer uses semi annual time periods.)