How to calculate quarterly returns from monthly returns

[worldCurrencies]

If i have 3 months of returns and price. How would I calculate quarterly return from the 3 months of data that I have? And why does quarterly return differ from monthly return?

 

[SullyWYO]

Is it a rolling quarter (the last 90 days), or is it a fiscal quarter (we are currently in Q3, consisting of 7/1/2022 - 9/16/2022).

There could be a few ways to define a quarter. Establish that first.

As for monthly returns versus quarterly returns, a quarterly return is the return from the quarter. A quarter is three months. A monthly return is the return from the month.