obtaining a mean value and {TAIL ~ a standard deviation} from {HEAD ~ said mean value} for one of said measured characteristics 
obtaining a mean value and { TAIL ~ a standard deviation } from { HEAD ~ said mean value } for one of said measured characteristics
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH