Before attending this lab, you should have read and be familiar with Chapter 3 section 3.7, and Chapter 5 section 5.8 of Delores Etter's Engineering Problem Solving with C. Answer the questions below in a typed document, numbered appropriately. Print out this sheet as a cover page. Bring the completed assignment to your next lab class. Write a function definition for a user-defined function that calculates the (floating-point double) Percent Difference between two experimental double values, A and B Percent Difference = |A - B/(A + B/2)| * 100% Write a function definition for a user-defined function that calculates the (floating-point double) Percent Error between a known double value, A, and an experimental double value B. Percent Error = |A - B/A| * 100% Write a function definition for a user-defined function that calculates the (floating-point double) mean of a specified column in a 2-D array that has NROWS rows and NCOLS columns. (NROWS and NCOLS are pre-defined symbolic constants) The parameters should be the double array and the desired column, as specified in the following function prototype: double col_mean (double x[NROWS, NCOLS], int col); Same as #3, but calculating the standard deviation rather than the mean. sigma = Squareroot 1/N sigma^N_i = 1 (x_i - x_avg)^2