Calc is not displaying the x and y axes correctly

I’m trying to graph this:

I want the column in ‘C’ to be on the x-axis, but even if I switch the positions between ‘C’ and ‘D’, it still displays 1,2,3 on the x-axis. I want the exact decimal numbers on the y-axis, though. Also, what is that orange line on the bottom on the graph? I would like to get rid of it.

You have selected the Line chart type. Try selecting the XY (Scatter) chart type instead.