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 1) 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. A -B A+ B Percent Difference = * 100% 2) 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- 3) 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): 4) Same as #3, but calculating the standard deviation rather than the mean. (xi - Xavg)