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Oct. 2nd, 2005 09:07 amMore probability and statistics from the brother in graduate school...
Suppose from a 40 person class you are going to select groups of 10 students at random (such that all samples are equally likely). You are interested in probability that a student, Buffy, is chosen.
A) First suppose that you are choosing students to award prizes, and you are willing to allow one student more then one prize. Consequently, you will sample 10 students from the class with replacement. This means you select one student and then put them (them is not an appropriate pronoun for "one student" no matter what the rest of the world does. I do not approve.) back in the selection pool. What is the probability Buffy with (I cut and paste these. Errors are in the originals.) be one of the students chosen?
B) Using this sampling approach, what is the probability of Buffy being chosen more then once?
C) Now suppose that instead of choosing students to award prizes, you are choosing students to staff a committee. Consequently, no student may be chosen more then once. What is the probablity of Buffy being chosen?
D) Explain why you expect the probability of Buffy being chosen to be higher when sampling is done without replacement.
( You gotta play to win... )
Suppose from a 40 person class you are going to select groups of 10 students at random (such that all samples are equally likely). You are interested in probability that a student, Buffy, is chosen.
A) First suppose that you are choosing students to award prizes, and you are willing to allow one student more then one prize. Consequently, you will sample 10 students from the class with replacement. This means you select one student and then put them (them is not an appropriate pronoun for "one student" no matter what the rest of the world does. I do not approve.) back in the selection pool. What is the probability Buffy with (I cut and paste these. Errors are in the originals.) be one of the students chosen?
B) Using this sampling approach, what is the probability of Buffy being chosen more then once?
C) Now suppose that instead of choosing students to award prizes, you are choosing students to staff a committee. Consequently, no student may be chosen more then once. What is the probablity of Buffy being chosen?
D) Explain why you expect the probability of Buffy being chosen to be higher when sampling is done without replacement.
( You gotta play to win... )
