Write comprehensively on the below topic.
topic : big data challenges and opportunity
note: the challenges should be stated with comprehensive explanation and also the opportunity should be stated and explained comprehensively.

The file sales data.xlsx contains monthly sales amounts for 40 sales regions. write a sub that uses a for loop to color the interior of every other row (rows 3, 5, etc.) gray. color only the data area, columns a to m. (check the file colors in excel.xlsm to find a nice color of gray.)

Which type of file can be used to import data into a spreadsheet?

Is an attack that relies on guessing the isns of tcp packets