Which indicates significance in hypothesis testing?

It depends on the variable types.

$2.$ Which company had the $($significantly$)$ higher inventory turnover ratio?

: Amazon

$3.$ Which company holds significantly more inventory to cover sales?

Walmart

$4.$ For the asset turnover ratio, if the data for Walmart and Amazon are swapped $($with Walmart on the left, Amazon on the right$),$ what happens to the t Stat value?

It changes from $-4\mathrm{.}26$ to $+4\mathrm{.}26$

$5.$ What alpha level was used for the hypothesis tests?