Excel Charts with Drop-Down lists

I have attached the workbook I'm using. I need to create a chart that changes as you select a different office from the drop-down menu on the 3rd worksheet. I need the chart to go to the 2nd worksheet and look for the information and give me a graph of the data. I put formulas in the 2nd sheet to give the data I was looking for from the 1st sheet. I don't know how to make Excel paste formulas into another workbook. My knowledge is limited. Could someone help me?

The original workbook has formulas on the 2nd worksheet that get information from the 1st worksheet and auto-fills the 2nd wroksheet. I don't know how to copy-paste entire worksheets which include formulas. That's why you don't see the formulas in this workbook... Just know they're there. My problem is that I want to create graphs for the data contained in the 2nd worksheet. I only know how to create a drop-down menu using data validation. I read a little about named ranges and the OFFSET funtion but I don't know how to get started with these.

Thank you! I figured this one out.