Data validation on list multiplaed in cell in tabels

Hello,

I have first tables with prices for products a and b.
I have second auxiliary list where I chose a currency and result of choosing it should be multiply the price(for product a and b.) in the first table with selected value currency.
I just do one click form list to change the currency and price of choosing currency in first table.

Thank you in advance for help.
currency.jpg

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