Using R

4. Write a function named mad_vec which computes the mean absolute deviation (MAD) for a data vector. Apply this function to the weight data. 5. Write a function named fibonacci which computes the Fibonacci sequence for arbitrary index n, i.e., 11, 22, ...,In. Obtain results for n = 9 and n = 20 Hint: It may be easiest to use a for loop here