Answer
$ \approx 2.747$
Work Step by Step
We are asked to use a calculator to compute the result in radian mode and then round-off the result to three decimal places.
We get:
$\cot (\dfrac{ 28 \pi}{9})=\dfrac{1}{\tan (\dfrac{ 28 \pi}{9})} =2.74747741945 \approx 2.747$
