已知一组数2,4,5,1,a的平均数为a,那么这一组数的标准差为______. 发布时间:2017-05-27 17:58 │ 来源:www.tikuol.com 题型:填空题 问题: 已知一组数2,4,5,1,a的平均数为a,那么这一组数的标准差为______.
题型:填空题 -Did you see the new movie directed by that famous director? It's said to be _______ great fun. -No. I have been busy repairing all the broken office _______ these days. A.a; equipmentB.the; equipments C.\ ; equipmentD.\ ; equipments 查看答案
题型:填空题 李勇面朝正北方向站在操场上,由于阳光照射形成的身影在他本身体的右侧,此时的时间大约是在______(填“上午”“中午”或“下午”);他手里拿着一瓶矿泉水,通过瓶子看到瓶后的手指变“粗”了,这是光的______现象,对于地面,瓶里的水具有______能. 查看答案
题型:填空题 Mr. Brown, a good friend of mine, __________ us but that he was short of money at the time.A.would helpB.would have helped C.had helpedD.helped 查看答案