哪位好心的NN能帮忙解答一下吗？多谢了！！！

qiuqiaomm

1.一数列平均数46，标准方差4，问：which value is exactly 1.5 standard deviations from the arithmetic mean of the set?  答案：50

2.一人在卡片上写了1到20这20个整数，然后每次任意抽一张不放回，为保证他抽出的所有卡片数字和为偶数，问要抽多少张？答案：12

3.一个连续数列 问中间又没有数是8的multiple

A 9-15

B 有10个数

bobiouou

3. A you don't know for sure

B yes if there is 10 number in a serie there must be a number that's / by 8 so B