How well is Costco performing from a financial perspective? Do some number$-$crunching

using the data in case Exhibit $1$ to support your answer. Calculate the following in an excel spreadsheet and use your results to help you diagnose Costco$$s financial performance:

$1.$ Gross profit margin

$2.$ Operating profit margin

$3.$ Net profit margin

$4.$ Earning per share

$5.$ Current liquidity ratio

$6.$ Working capital ratio

$7.$ Total debt$-$to$-$assets ratio

$8.$ Long$-$term debt$-$to$-$assets ratio

$9.$ Debt to equity ratio

$10$: long term debt to equity ratio

$11.$ times interest earned $($coverage$)$ ratio

$12$: days of inventory ratio

$13$: inventory turnover ratio

$14$: average collection period ratio

$15.$ total return on assets