几个问题

NO.PZ2020021204000034问题如下 A bonthcliverein the cember 2018 ten-yeTreasury note futures contrais a bonwith maturity on April 15, 2026, thpays a coupon of 4% per annum.When the yielis 6% per annum(with semi-annucompounng) ， calculate the conversion factor for the bon The bons time to maturity on the first y of the livery months is seven years (cember 2018 to cember 2025) an4.5 months (January 2026 to miApril 2026).This is rounto seven years anthree months. The rty priof a seven yeanthree-month bonimmeately before the coupon payable in three months is ∑i=01421.03i+1001.0314=90.7039\sum_{i=0}^{14}\frac2{1.03^i}+\frac{100}{1.03^{14}}=90.7039∑i=014​1.03i2​+1.0314100​=90.7039when the yielis 6%. The rty priof the bonthree months earlier is90.70391.03=89.3732\frac{90.7039}{\sqrt{1.03}}=89.37321.03​90.7039​=89.3732Subtracting the accrueinterest of 1, we get a clepriof 88.3732 anthe conversion factor is 0.8837.烦请具体写下该类题怎么解答，多谢。

NO.PZ2020021204000034问题如下 A bonthcliverein the cember 2018 ten-yeTreasury note futures contrais a bonwith maturity on April 15, 2026, thpays a coupon of 4% per annum.When the yielis 6% per annum(with semi-annucompounng) ， calculate the conversion factor for the bon The bons time to maturity on the first y of the livery months is seven years (cember 2018 to cember 2025) an4.5 months (January 2026 to miApril 2026).This is rounto seven years anthree months. The rty priof a seven yeanthree-month bonimmeately before the coupon payable in three months is ∑i=01421.03i+1001.0314=90.7039\sum_{i=0}^{14}\frac2{1.03^i}+\frac{100}{1.03^{14}}=90.7039∑i=014​1.03i2​+1.0314100​=90.7039when the yielis 6%. The rty priof the bonthree months earlier is90.70391.03=89.3732\frac{90.7039}{\sqrt{1.03}}=89.37321.03​90.7039​=89.3732Subtracting the accrueinterest of 1, we get a clepriof 88.3732 anthe conversion factor is 0.8837.为什么要折三个月，利息为什么是1

NO.PZ2020021204000034问题如下 A bonthcliverein the cember 2018 ten-yeTreasury note futures contrais a bonwith maturity on April 15, 2026, thpays a coupon of 4% per annum.When the yielis 6% per annum(with semi-annucompounng) ， calculate the conversion factor for the bon The bons time to maturity on the first y of the livery months is seven years (cember 2018 to cember 2025) an4.5 months (January 2026 to miApril 2026).This is rounto seven years anthree months. The rty priof a seven yeanthree-month bonimmeately before the coupon payable in three months is ∑i=01421.03i+1001.0314=90.7039\sum_{i=0}^{14}\frac2{1.03^i}+\frac{100}{1.03^{14}}=90.7039∑i=014​1.03i2​+1.0314100​=90.7039when the yielis 6%. The rty priof the bonthree months earlier is90.70391.03=89.3732\frac{90.7039}{\sqrt{1.03}}=89.37321.03​90.7039​=89.3732Subtracting the accrueinterest of 1, we get a clepriof 88.3732 anthe conversion factor is 0.8837.为什么I从0到14，而不是从1到15呢？也就是2/1.03+2/1.03的平方……第二部分往前折现3个月，为什么分母是1.03的平方根，而不是(1+6%/4)1/4呢

NO.PZ2020021204000034 问题如下 A bonthcliverein the cember 2018 ten-yeTreasury note futures contrais a bonwith maturity on April 15, 2026, thpays a coupon of 4% per annum.When the yielis 6% per annum(with semi-annucompounng) ， calculate the conversion factor for the bon The bons time to maturity on the first y of the livery months is seven years (cember 2018 to cember 2025) an4.5 months (January 2026 to miApril 2026).This is rounto seven years anthree months. The rty priof a seven yeanthree-month bonimmeately before the coupon payable in three months is ∑i=01421.03i+1001.0314=90.7039\sum_{i=0}^{14}\frac2{1.03^i}+\frac{100}{1.03^{14}}=90.7039∑i=014​1.03i2​+1.0314100​=90.7039when the yielis 6%. The rty priof the bonthree months earlier is90.70391.03=89.3732\frac{90.7039}{\sqrt{1.03}}=89.37321.03​90.7039​=89.3732Subtracting the accrueinterest of 1, we get a clepriof 88.3732 anthe conversion factor is 0.8837. 这个题的解析里面，先折了7年的，又折了三个月的，可以这样做吗，还有类似的这样的题吗