Help please

[jack1e]

Hello I am trying to get the total sales per customer. I have tried  samples from many sources but nothing that gives me what I need. I am ultimately trying to get a weighted profit margin but first I need to know total sales for each customer. I have included my sample which is much smaller than the original but with some of the same data. Thank you in advance

[jack1e]

I would like for BI to sum total sales by customer. This is just a sample and my file is much bigger than this but this will give  you an idea of what I am trying to do.  

Customer	Item ID	Total Sales
John Smith	124568	63,258
Mary Shelly	124569	54,247
Robert August	124570	39,258
Gene Campbell	124571	71,269
Amy Waters	124572	40,123
John Smith	54789	21,000
Mary Shelly	789456	11,321

[PijushRoy]

@jack1e 

Can you please paste sample raw data, not as a image, and what is output you expect.

Please share