File Input Output

• Problem 1: xls_numbers_read.m and random_stuff.xlsx
• Problem 3: xls_read_areas.m and continent_areas.xlsx
• Problem 5: xls_annotated_array_write.m
• Problem 7: txt_numbers_write.m
• Problem 9: txt_numbers_read.m
• Problem 11: bin_numbers_write.m
• Problem 13: bin_numbers_read.m