please answer the following questions with proper calculations and explanation

3. You also have to prepare a spiked sample of the same fertilizer. The spiked samples should contain 2.5 ppm copper from the fertilizer, and an additional 1 ppm copper that you will add using either the 100 or the 1000 ppm standard solution. Calculate the volume of copper spike you will use and describe how you will prepare this solution. 4. I have a sample solution that I have analyzed for chromium. I have now been told to prepare a known volume of this solution to contain an additional 2.0 ppm of chromium (using my 1000 ppm chromium standard to do so). I do not know how much of the original sample solution that I have, except that it is less than 50 mL and I do not want to use it all up to make this new solution. Tell me, in detail, exactly how you will prepare this solution. Show your calculations