4.13 Columbus, Wisconsin and Mandan, North Dakota Five-pound samples of powdered milk have been obtained weekly from milk powdering plants in Columbus, Wisconsin (powdered whole milk) and Mandan, North Dakota (powdered buttermilk) and composited on a monthly basis. Table 15 summarizes the data in jyc 8r90/g Ca, and 10 graphically illustrate the data. The error term is one standard deviation from the mean of replicate analyses. - 88 « Figures 9