A beer manufacturer, Lightdraft, Inc., wishes to estimate its proportion of the market in an urban area. A grocery chain agrees to supply the company with the proportion of six-packs of Lightdraft...

A beer manufacturer, Lightdraft, Inc., wishes to estimate its

proportion of the market in an urban area. A grocery chain

agrees to supply the company with the proportion of six-packs

of Lightdraft sold during a given week among all six-packs sold.

Of 1600 sold, 320 are Lightdraft. Find a 95 and 99% confidence

interval for the true market share.