题目: 数据-1,0,1,2,3的标准差为______. 答案: 数据-1,0,1,2,3的平均数为 .x=15[-1+0+1+2+3]=1方差为S2=15[(-1-1)2+(0-1)2+(1-1)2+(2-1)2+(3-1)2]=2∴标准差为 2.故答案为2.
题型:选择题 —Are you going shopping with me, Alice? —_____.A. Yes, we are B. Yes, I am C. Yes, they are D. Yes, she is 查看答案