The one$-$year T$-$Bill rates for the next four years are expected to be as follows:

$R1=6\mathrm{.}25\%E2R1=6\mathrm{.}91\%E3R1=7\mathrm{.}18\%E4R1=8\mathrm{.}55\%$

Estimate the equilibrium rate in accordance to the unbiased expectations theory for $3-$year spot

bonds. Show your answer to $5$ decimals places. Please show your work$-$no points awarded without

showing the process for estimating this rate.