Thenumbers2,4,6,9and12arerearrangedaccordingtotheserules;
(1)Thelargestisn'first,butitisinoneofthefirstthreeplaces.(2)Thesmallestisn'tlastbutitisinoneofthethreeplaces.(3)Themedianisn'tfirstorlastnumbers?Whatistheaverageofthefirstorlastnumbers?Answer:_________(要有答案和过程)