Last year, Cayman Corporation had sales of $$28$ million, total variable costs of $$13$ million, and total fixed costs of $$5,000,000.$ In addition, they paid $$4$ million in interest to bondholders. Cayman has a marginal tax rate of $21$ percent. If Cayman's sales increase by $15\%,$ what should be the increase in operating income? SET YOUR CALCULATOR TO $4$ DECIMAL PLACES THEN ROUND TO $2$ DECIMAL PLACES AT THE END. DO NOT ENTER THE $\%$ SIGN. FOR EXAMPLE, IF YOUR ANSWER IS $12\mathrm{.}7125,$ ENTER IT AS $12\mathrm{.}71.$