Consider the column "length" in the data frame df. What does this line of code do? df["length"] = (df["length"]-df["length"].mean())/df["length"].std() 1 point It calculates the standard deviation of the values in the length column It finds the mean of the values in the length column and divides by the standard deviation It finds the number of standard deviations that each value is from the mean of the values in the "length" column It standardizes the values in the "length" column