My excel chart is a graph of Interest's share and Principal's share of each
Monthly Payment of the 360 payments of a 30-year mortgage. It's a nice
continuous graph that shows the point where Principal's share becomes
dominant (at 18.5 years).

All i've wanted to do these past three days is have an x-axis labeled with
tick marks starting at 0, ending nicely at exactly 30 , and with the tick
marks 5,10, 15, 20 and 25 in between.
Why is this so difficult a challenge?
Why did i have to buy that $25.00 dummies book and still not find the answer?

Thanks for the help.