Kellogg Company manufactures cereal and other convenience food under its many well$-$known brands such as Kellogg$$s$,$ Keebler$,$ and Cheez$-$It$.$ The company, with over $$13\mathrm{.}5$ billion in annual sales worldwide, partially finances its operation through the issuance of debt. At the beginning of its $2015$ fiscal year, it had $$6\mathrm{.}6$ billion in total debt. At the end of fiscal year $2015,$ its total debt had increased to $$6\mathrm{.}7$ billion. Its fiscal $2015$ interest expense was $$327$ million, and its assumed statutory tax rate was $37\%.$

a$.$ Compute the company$$s average pretax borrowing cost. $($Hint: Use the average amount of debt as the denominator in the computation.$)$

Round your answer to one decimal place $($ex: $0\mathrm{.}0345=3\mathrm{.}5\%)$