Use a financial calculator: $(10$ points$)$ A perpetuity immediate with semi$-$annual payments pays $100,100,200,200,300,300,400,400,500,500,$dotsdots.. Based on a nominal interest rate of $i>0$ convertible semi$-$annually, the present value is $21512\mathrm{.}19512.$ A perpetuity immediate having semi$-$annual payments of $100,200,300,400,$dots.. $,800,900,1000,1000,1000,1000,1000,$dots.. has a present value of $x$ based on a nominal interest rate of $i>0$ convertible semi$-$annually. Find $x.$