First of all as we know there are hundreds of currency pairs that are interconnected to each other. Like taking your example we have a pair of EUR/AUD on the other hand we also have a pair of EUR/USD and AUD/USD. Thus any news on USD will make changes with some percentage on the latter currency pairs; the amount of change depends on the type of news. Thus the effect on the latter two currency pairs will automatically affect currency pair of EUR/AUD.
Accounting
firms near me 6530 Trask Terrace Alexandria. Suppose, due some news on USD the Currency pair of EUR/USD appreciated by 2% and AUD/USD appreciated by 1.5%. Now mathematically cross multiplying the pair EUR/USD = AUD/USD, we cancel the common term i.e. USD. So the net effect on apperception of respective currencies will thus effect remaining pair EUR/AUD.
At the end you should also be concerned about different factors like type of news, country economy, globally affecting factors. We should also look technically and fundamentally what that pair is predicting.