The Jon Peltier from Peltier Tech had the courtesy to visit my blog and leave a comment. Thank you Jon for this gesture. It's a real honor.
My Excel charting skills wouldn't be where they are today if it wasn't for the pioneering work of two people: Jon and his blog and the legendary John Walkenbach (retired). Highly recommend checking their work.
Here below are Jon's comments:
Simplifications to your page,
Step 23: Select the range F10:G30 (not G10:G30)
Step 24: Right click the new series in the chart (either series actually), select "Change Series Chart Type".
Delete Step 25 (Step 24 made it unnecessary)
Delete Steps 28-31 (Step 23 made these unnecessary).