Forward Rates Question

Hi,

I came across this question and I do not understand the solution. Would someone please be able to provide an explanation?

Assume the following six-month forward rates (presented on an annualized, bond-equivalent basis) were calculated from the yield curve.

Notation Forward Rate 1f0 0.50% 1f1 0.70% 1f2 1.00% 1f3 1.50% 1f4 2.20% 1f5 3.00% 1f6 4.00%

The 3-year spot rate is closest to:

A. 0.74%. B. 1.48%. C. 2.06%.

ANSWER:

z6 = [1.0025 × 1.0035 ×1.0050 × 1.0075 × 1.0110 × 1.0150]1/6 – 1 = 0.0074 × 2 = 1.48%.

Why are they using Z6 ?

thanks!

Because time is measured in half-years: 3 years = 6 half-years.