A price-earnings ratio or P/E ratio is calculated as a firm’s share price compared to the income or profit earned by the firm per share. Generally, a high P/E ratio suggests that investors are expecting higher earnings growth in the future compared to companies with a lower P/E ratio. The following table shows the P/E ratios for a sample of firms in the footwear industry:

FirmP/E Ratio

Brown Shoe Co., Inc.......26

CROCS, Inc. ...........13

DSW, Inc. ...........21

Foot Locker, Inc. ............16

Nike, Inc. ...........21

Let these ratios represent a random sample drawn from a normally distributed population. Construct the 90% confidence interval for the mean P/E ratio for the entire footwear industry.