The Global fisherypacks shrimps that weigh more than 1.91 ounces each in packages marked 'large"and the shrimp that weigh less than 0.47 ounces each into packages marked "small", the remainer are packed in "medium size packages. If a day's catch showed that 19.77 percent of the shrimps were large and 6.06 percent were small, determine the mean and standard deviation for the shrimp weights. Assume that the shrimps' weight are normally distrubuted.