單項(xiàng)選擇題
采用移動(dòng)平均法修勻時(shí)間數(shù)列時(shí),所得的移動(dòng)平均數(shù)組成的新時(shí)間數(shù)列的項(xiàng)數(shù)比原時(shí)間數(shù)列的項(xiàng)數(shù)少。如果原時(shí)間數(shù)列有20項(xiàng),選用5項(xiàng)進(jìn)行移動(dòng)平均,則所得到的移動(dòng)平均數(shù)時(shí)間數(shù)列的項(xiàng)數(shù)有()
A.15項(xiàng)
B.16項(xiàng)
C.17項(xiàng)