The question asks for the calculation of a cumulative probability for a binomial distribution X∼B(n,p). Students are expected to use the complement rule P(X>k)=1−P(X≤k) and a GDC to find the result.
For X∼B(100,0.8), calculate P(X>65).
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Question 3
Skill question
Given X∼B(20,p) with variance 5, find p.
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Question 4
Skill question
A lightbulb manufacturer has a defect rate of 8%. In a batch of 200 bulbs, let X be the number of nondefective bulbs. Find P(X≥190).
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Question 5
Skill question
Let X∼B(n,p) and suppose its standard deviation equals half its mean. Find a relation between n and p.
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Question 6
Skill question
A student guesses randomly on 15 true/false questions (p=0.5). If X is the number of correct answers, find P(X≥12).
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Question 7
Skill question
Let X∼B(20,0.3). Find P(X≥5).
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Question 8
Skill question
Topic 4: Statistics and probability — Binomial distribution
For X∼B(80,0.7), calculate the expected value and the standard deviation of X.
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Question 9
Skill question
Let X∼B(n,p) satisfy E(X)=10 and Var(X)=6. Find n and p.
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Question 10
Skill question
In 15 independent transmissions, the probability of success is 0.2. If X is the number of successful transmissions, find E(X) and Var(X).
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Question 11
Skill question
For X∼B(n,p), determine p if the mean is twice the variance.
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Question 12
Skill question
If X∼B(50,0.6), find the expected value E(X) and the variance Var(X).