统计概率A test consists of 20 multiple choice questions.Each que
沙漠之南2022-10-04 11:39:541条回答
统计概率
A test consists of 20 multiple choice questions.Each question has 5 possible answers,of which only one is correct.If a student guesses on each question,find the following：
1) estimate the probability of the number of correct answers that will fall within the limits μ±3σ
A test consists of 20 multiple choice questions.Each question has 5 possible answers,of which only one is correct.If a student guesses on each question,find the following：
1) estimate the probability of the number of correct answers that will fall within the limits μ±3σ
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jimhawl 共回答了12个问题 |采纳率66.7%- 设X为‘the number of correct answers’
X服从n=20,p=1/5的二项分布,即B(20,1/5）,分布律为
P(X=k)=C(20,k)*(1/5)^k*(1-1/5)^(20-k),k=0,1,2,…20
μ=EX=np=4
σ=√DX=√np(1-p)=4√5/5
P(μ-3σ - 1年前
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whf93971年前1 -
zhuchengbing 共回答了17个问题
|采纳率88.2%好题1年前查看全部
- 数学统计概率 (2 12:49:43)
数学统计概率 (2 12:49:43)
已知,一个样本a,b,4,5,3,其中a,b为实数,且满足关系式a2+b2_2a--4b+5=0,则它的方差是（ ）,标准差是（ ）kqc30001年前4 -
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|采纳率91.7%把那个等式变形一下
得（a-1）^2+(B-2)^2=0
所以a=1,b=2
那么样本为12345
平均数3
方差为（4+1+4+1)/5=2
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野孩子ZY1年前3
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lb75330 共回答了15个问题
|采纳率100%给个大致准确的翻译吧：
统计符号表达式
我在 使用HP38G图形计算器教学讲义
第一讲 HP38G的键盘和通常函数计算器的功能
里看到了这个.而且研究了一下.应该就是这个意思了.1年前查看全部
- 大学统计题目SupposeX ∼ N(µ,σ2).If 10% of the probability is below
大学统计题目
SupposeX ∼ N(µ,σ2).If 10% of the probability is below 60 and 5% is above 90,
(a) What are the values of µ and
(b) What is the value c such that the interval(µ −c,µ + c) includes 98% of all values?tristanyuan1年前1 -
fengxueqin99 共回答了19个问题
|采纳率89.5%P(X90)=1-P(X1年前查看全部
大家在问
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- 3设xy+lny+lnx=1,求dy/dx│x=1
- 4这个图中的116是什么意思?
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- 7马丁路德金 关于信念的一句名言.
- 8如图,Rt△bac中ab=ac,∠bac=90,ad⊥bc于点d,点f.e.分别在ad.dc上,且af=ce连接bf.a
- 9It remains unknown who will ______ Mr. White when he goes ab
- 10甲乙丙丁四人现在的年龄和是64岁,甲现在32岁,乙21岁,甲18岁时,丙的年龄是丁的3倍,丁现在多少岁?
- 11用适当的化学符号和数字回答：（1）二个氮原子______
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