A.算術(shù)均數(shù)和中位數(shù) B.算術(shù)均數(shù)和幾何均數(shù) C.算術(shù)均數(shù)、中位數(shù)和變異系數(shù) D.算術(shù)均數(shù)和標準差 E.以上都不是