Today is 1 July, 2019. Siobhn has a portfolio which consists of two different types of financial instruments (henceforth referred to as instrument A and instrument B). Siobhn purchased all instruments on 1 July 2011 to create this portfolio, which is composed of 21 units of instrument A and 39 units of instrument B. - Instrument A is a zero-coupon bond with a face value of $100. This bond matures at par. Its maturity date is 1 January 2029. - Instrument B is a Treasury bond with a coupon rate of j2=2.29% p.a. and a face value of $100. This bond matures at par. Its maturity date is 1 January 2022. Calculate the current duration of Siobhn's portfolio using a yield to maturity of j2=2.58% p.a. Express your answer in terms of years and round your answer to two decimal places. a. 4.55 years b. 4.59 years c. 6.74 years d. 6.05 years Lydia just purchased a Treasury bond for $89.61 at a yield rate of j2=9.54% p.a. The duration of Lydia's bond is 6.7337 years. Using the bond price sensitivity formula, calculate the change in price of Lydia's bond that would result from an increase in the yield rate (j2) of 38 basis points. Round your answer to four decimal places. (The values below are all in dollars.) a. -2.1886 b. -2.0933 c. -1.0466 d. -1.0943