Question

求高手解答英文数学题目！！！！ 要一步一步的步骤

Q1. 1.3% of the company's production of a certain component is defective.
(a) what is the probability that the quality inspector will find at 3 defectives when taking a random sample of 74 components?
(b) how large a random sample of components would the inspector need to take to be at least 83% sure of finding at least one defective?

Answer 1

(a) Put P = Probabilty of having 3 defectives in 74 samples
P = C(74,3) x (1.3%)^3 x (100%-1.3%)^(74-3)
= 74! / (74-3)!3! x (1.3%)^3 x (100%-1.3%)^(71)
= (74x73x72) / (3x2x1) x (0.013)^3 x (0.987)^(71)
= 0.0562 or 5.62%

(b) Assume N is the no. of sample tested, 83% = 1 - (100%-1.3%)^N,
0.987^N = 0.17
N log(0.987) = log(0.17)
N = 135.41
Since N is a integral, therefore, N =136.

但要注意你的问题（a) 里面" ... the Quality inspector will find at 3 defectives ... “ 语法不对， 不知道你是要表达"will find 3 defectives" 还是 "will find at least 3 defectives"。如果是后者答案就完全不一样。

追问

我少打了个least 应该是后者 那应该怎么做 你方不方便给我一个联系方式 我还有其他2道题目想问

Answer 2

1.3%的公司生产的一个特定的组件是有缺陷的。
　　(一)的机率是多少质量检验员会发现3拍照的时候英美法系的随机抽取了74名组件?
　　(b),是何等的大部件会随机抽样检查员需要至少有83%的肯定找到至少一个缺陷吗?

追问

我要的是解答

Answer 3

如果你要翻译的话我现在可以认真自己翻给你……
如果是解答你得等等……
你可以试试枚举法……我帮你问问同学

追问

我要的是解答