If movies is a table containing the column Gross and we run these lines of code import numpy as np np.average(movies.column[Gross?]) what is the result? The sum of the values of the variable Gross in this data set An error message The median value of the variable Gross in this data set The mean value of the variable Gross in this data set What is the result of running this line of code? type(3) int str An error message numpy.ndarray