um número que tirei do rabo

 ... Anglo’s former head of retail banking, Mr Bowe appears to describe how the bank cynically lured the government into a €7bn rescue in full knowledge that the sum would be nowhere near enough to save the lender. The thinking, he suggested, was that once Dublin had been “pulled in”, it would have no choice but to keep picking up the tab.
In the end, the Irish government was forced to pump €30bn into Anglo and roughly the same amount into Ireland’s two other cash-strapped banks, Bank of Ireland and Allied Irish Bank – rescues that brought the entire Irish economy to its knees.
On tape, Mr Fitzgerald asks Mr Bowe how he arrived at the €7bn figure. Referring to a nickname for the bank’s disgraced former chief executive David Drumm, Mr Bowe is heard saying: “Just as Drummer would say, ‘picked it out my arse’.”

Telegraph

Fitzgerald:
- Como é que chegaste à cifra de 7.000 M€?
Bowe:
- Foi um número que "tirei do rabo"...