Answer
Please see the work below.
Work Step by Step
We know that
$\Delta E_{int}=f_kd$
$\Delta E_{int}=\mu_k mg$
This can be rearranged as:
$\implies \mu_k=\frac{\Delta E_{int}}{mgd}$
We plug in the known values to obtain:
$\mu_k=\frac{\Delta E_{int}}{mgd}$
We plug in the known values to obtain:
$\mu_k=\frac{1500}{33\times 9.8\times 6.2}$
$\mu_k=0.75$
