Selected balance sheet and income statement

($millions)	2013	2012	2011
Net sales	$3,794	$3,643	$3,085
Interest expense	59	49	54
Pretax income	644	665	547
Net income	416	439	368
Current assets	3,152	2,890	2,685
Total assets	4,631	4,159	3,736
Current liabilities	587	627	480

Required

1. Compute the current ratio for each year and discuss any trends. Do you feel that the company is sufficiently liquid? Explain. What additional information might be helpful in analyzing the liquidity?
2. Compute times interest earned for each year and discuss any trends. Do you have any concerns about its level of financial leverage and its ability to meet interest obligations? Explain.