Ignore Currencies? Percentage Question (to work out total achievement, must all figs be in 1 currency?)

[Barbados5]

Hi, A sales person has targets & sales in three countries with their own currencies.
The sales persons achievement in each country can easily be calculated ...Sales/Target as a %.
But to work out the total achievement must the targets and sales all be converted to one currency?

Or as shown in the picture can the currencies be ignored and the target and sales columns be added up to give the total 90.56%

Thanks for the assistance

 

[Dr.Peterson]

Yes, you have to convert the currencies to one standard, because their relative amounts determine the weighting of the average.

For example, suppose (to keep it simple) that GBP and USD had the same value, but 1 EUR = 10 USD. Then the Ireland numbers would be multiplied by 10, and the average would be weighted heavily toward that, pulling the average down from what you show.

I suppose it could be done in other ways, but any method would have to take into account the various exchange rates.