$[$The following information applies to the questions displayed below.$]$

Haru is a self$-$employed cash$-$method, calendar$-$year taxpayer who made the following cash payments related to his business this year.

Calculate the after$-$tax cost of each payment assuming Haru has a $37$ percent marginal tax rate.

Note: Do not round intermediate calculations and round your final answer to the nearest whole dollar amount.

b$.$ $$1,600$ of interest on a short$-$term loan incurred in September and repaid in November. Half of the loan proceeds was used immediately to pay salaries and the other half was invested in municipal bonds until November.