Question

概率问题

我的问题是
16人的准确率是95%
16人全对的概率是0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95=0.6634

15人对的概率是多少
14人对的概率是多少

求公式和 详细步骤 我初中毕业 各位说的明白点,谢谢了.

如果16人里7人是95%.3人是94%.4人是90%.2人是98%.
16人全对的概率是0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.94*0.94*0.94*0.94*0.90*0.90*0.90*0.90*0.98*0.98=???????

15人对的概率是多少
14人对的概率是多少

Answer 1

首先请问95%是每人对的概率吗?如果是的话
那么
十五人对的概率是 0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.05
十四人对的概率是 0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.05*0.05

如果16人里7人是95%.3人是94%.4人是90%.2人是98%.
十五人全对的概率是
（7除以16）*0.05*0.95*0.95*0.95*0.95*0.95*0.95*0.94*0.94*0.94*0.90*0.90*0.90*0.90*0.98*0.98+（3除以16）*0.06*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.94*0.94*0.90*0.90*0.90*0.90*0.98*0.98+（4除以16）*0.10*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.94*0.94*0.94*0.90*0.90*0.90*0.98*0.98+（2除以16）*0.02*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.94*0.94*0.94*0.90*0.90*0.90*0.90*0.98
即使先选出不对的那个人的概率和错误率，然后剩余对的人的概率照写即可。

Answer 2

错的概率是5%
15人对的概率是0.95的15次方乘0.05
14人对的概率是0.95的14次方乘0.05的平方

Answer 3

15人对：需要一人答错，可以为任何一人答错，有16种答法
16*5%*（15个95%相乘）
14人对：需要2人答错，有16*15/2=120种答法
120*5%*5%*（14个95%相乘）

15人对：分四种情况，1：答对为95%的7人中有一位错的p1
2：………94%…3…………………p2
3: ………90%…4…………………p3
4: ………98%…2…………………p4
p1=7*5%*(6个95%相乘)*0.94*0.94*0.94*0.94*0.90*0.90*0.90*0.90*0.98*0.98
p2=3*6%*(2个94%相乘)*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.90*0.90*0.90*0.90*0.98*0.98
p3=4*10%(3个90%相乘)*0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.94*0.94*0.94*0.94*0.98*0.98
p4=2*2%*98%0.95*0.95*0.95*0.95*0.95*0.95*0.95*0.94*0.94*0.94*0.94*0.90*0.90*0.90*0.90
p=p1+p2+p3+p4
14人答对的分组太多了 不太方便写