Excel Graphing Help

Hello, I have been tasked to find out our optimal level of efficiency and I have had trouble trying to figure out how to graph this. I have 52 weeks, Cost, and then units in another. I know how to use standard deviation and normal distribution but I really don't know how I should graph this to get the results I'm looking for. I tried using a bell chart and a run chart looked the best with the mean and upper and lower control limits but I could only graph that using cost or units not both. Any help would be great.