The commodity prices worksheet contains several years' worth of data for certain commodities, but we will consider only the Nickel commodity.. You should use all of the Nickel data in the file but assume that data is a sample. What is the standard deviation of the Price Index for Nickel (rounded to the nearest 4 decimal places)? example 12.33414 --> 12.3341 example 48.39208 --> 48.3921