Suppose you are given the yields on the following Treasury securities$.$ For simplicity, assume that there is no maturity risk premium.

Security

Yield

$($Percent$)$

$1$year $4\mathrm{.}10$

$2$year $5\mathrm{.}40$

$3$year $6\mathrm{.}90$

$4$year $8\mathrm{.}40$