About the USD to AUD rate
The Australian dollar is heavily influenced by demand for the commodities Australia exports — particularly iron ore and coal — which means Chinese economic data often moves AUD/USD almost as much as Australian or US news does.
For Australians traveling to the US, or Americans visiting Australia, this rate has swung meaningfully over the years depending on the commodity cycle and the gap between Reserve Bank of Australia and US Federal Reserve interest rates.
Because Australia's economy is so trade-exposed, this pair is sometimes used by traders as a rough proxy for global growth sentiment — when investors are optimistic about global trade, the Aussie dollar has tended to benefit.