$17.$Consider the following portfolio:

Bond

Market Value

Duration

W

$$13$ million

$2$

X

$$27$ million

$7$

Y

$$60$ million

$8$

Z

$$40$ million

$14$

a$.$What is the portfolio$$s duration?

b$.$If interest rates for all maturities change by $50$ basis points, what is the approximate percentage change in the value of the portfolio?

c$.$What is the contribution to portfolio duration for each bond?

$18.$If two portfolios have the same duration, the change in their value when interest rates change will be the same.$$ Explain why you agree or disagree with this statement.$$