Maths question, not an average but a……

I have 15 subjects, and I have 7 measures/scores of those subjects, each measure/score has a different level of importance.

Can I create an overall score that adds the 7 measures/scores together but takes into consideration the level of importance?

If it’s possible to create an excel formula to do the above, even better.

sure,  just multiply each score by the importance number and divide by the sum of those importance numbers.  Take a simpler case of two subjects a & b with a weighting of each where a =3 and b=5 (more important).  The average will be

(a * 3 + b * 5) / (3 + 5)

As always you can check your Excel formula by setting the weighting to everything apart from one of the subjects to zero, then the average will just be the value of the subject.  So if the weighting of b above was zero then the average would be (a * 3)/3 or just a.  Set all the weightings to 1 and the average is just the average ie. (a + b)/2

Weighted Average is what you’re talking about

https://support.microsoft.com/en-gb/office/video-weighted-average-c1ad3cd4-cf64-4461-b3b7-0767498b2135#:~:text=We’ll%20use%20the%20SUMPRODUCT,the%20SUM%20of%20the%20weights.