$+$set$401$k$()$: static double $1.$ Prompt $5.2.$ Returns the $401$k contribution as a percentage of salary by calling validateDecimals$()$ and sending it input.hasNextDouble$()$ as the first argument and the second argument. $+$test$401$k$()$: static double $1.$ Prints message. $2.$ Returns the $401$k contribution as a percentage of salary by calling validateDecimals$()$ and sending it input.hasNextDouble$()$ as the first argument and the second argument. $+$formatDollarSign$($employeeName: String, grossPay: double, empl$401$k: double$)$: static String $1.$ Receives the employee name, the gross pay, and the $401$k contribution amount. $2.$ Returns the formatted String with a dollar sign that is added to the payroll expense report. String.format$("\%$n$\%-30$s $\%8$s $$\%,15\mathrm{.}2$f $\%8$s $$\%,13\mathrm{.}2$f$",$ employeeName, $"",$ grossPay, $"",$ empl$401$k$)$;