Can't Change Min/Max on Axes...why?!

I'm doing a regression on ERA and Win% from the top 50 strikeout
leaders of all time. That means my data ranges between 2.00-4.00 and
0.4-0.7. Excel has automatically created the range for the x and y axes
on my chart as 0.000-0.8000 (x) and 0.00-4.50 (y). As you can imagine,
this has caused my data to cluster in a small portion of the graph.

I went to the chart, selected the x-axis and went to "format axis." I
changed the minimum from 0 to 0.4. It doesn't have an effect on the
chart, and when you go back to "format axis" again, it displays the
minimum as zero.

Is there a way to change this? I know how to do it on my graphing
calculator, but I can't seem to do it in excel. I searched the
preferences and changed off every option I could find that had the word
locked in it, but to no avail. MS Office's help guide was useless as
ever.

Thanks!