Dynamically Extending the Range, in a Formula, to Include Added Rows

Hello everybody!

I face this problem quite often; that when I have to Add New Rows, at the end of my data, I have to modify my formula in order to cover the newly added rows. Just as an example;

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How can I write the formula that; when I add more rows after Row 50; it covers the new range. Please note that I have a different segment of data at the bottom, and therefore;
I can NOT use the formula like;

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Any help is appreciated.

Regards.

Thanks, Glenn, for your attention.
Actually, I am Not very well-versed with Excel. My data has grown quite much, and I had been using the traditional way of calculations. I wonder' if I switch over to the Data table, I may have to go through plenty of modifications and spend long hours for that.
I would appreciate, if you elaborate on the way to go about the data table, without sweating for hours.

Thanks in anticipation.

I feel obliged for your help. I have attached just a very short Sample Worksheet, for your reference.

Thanks in anticipation.

Well done, Glenn. So, this is the Data Table! I had been using it without knowing its name.
Thank you very much for the lesson, and have a great time.

Regards.