Rubbish in statistics (3)
I believe the answer is:
tat
'rubbish' is the definition.
(low-quality items or material)
'in statistics' is the wordplay.
'in' says the answer is hidden in the clue.
'TAT' is hidden in the letters of 'statistics'.
(Other definitions for tat that I've seen before include "Inferior articles" , "Tawdry and shabby article" , "Worthless items" , "Shoddy articles" , "Utterly tasteless objects" .)