I believe step $1$ is inaccurate:

Initial Margin:

The initial margin for $10$ COMEX gold futures contracts is $7\%$ of the initial price, which is: $7\%*864*10$ is not $$5820$ it is $604\mathrm{.}8$

Maintenance Margin:

The maintenance margin is $5\%$ of the initial price, which is: $5\%864*10$ is not $$4320,$ it is $$432$

Please advise,