On top of the vegetables list are cucumber and lettuce, consisting of 96 percent water. Zucchini, radish and celery are comprised of 95 percent water. Ninety-four percent of tomato's weight is water, and green cabbage is 93 percent water.
I looked at the process sigma calculator (button in upper right below the search box) and they present a link to a forum post (http://www.isixsigma.com/forum/showmessage.asp?messageID=437) that gives information on calculating the sigma using a normsinv function.
Sigma is the eighteenth letter of the ancient Greek alphabet. As an upper case letter (), it is used as a symbol for sums and series. As a lower case letter () it is a prefix used in several contexts to indicate that a term is referred in some way to countable unions.