[dba-Tech] Excel X Axis

Dear List:
 
When I create a simple chart in Excel, the x axis always seems to be labeled
by the row number.  I've got a chart that shows the values in column C as a
line graph.  And the values on the Y axis are correct.  
 
But the x axis shows the row number on the sheet.  I'd like it to use the
values in Column A for the x axis labels.  But I can't figure out how this
is done.
 
Can someone give me a push in the right direction?
 
MTIA
 
Rocky