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d) What is the expected value of X? e) What is the variance of X? [

d) What is the expected value of X? e) What is the variance of X? [

A First Course in Probability (10th Edition)
A First Course in Probability (10th Edition)
10th Edition
ISBN:9780134753119
Author:Sheldon Ross
Publisher:Sheldon Ross
Chapter1: Combinatorial Analysis
Section: Chapter Questions
Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...
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It is known that 45% of new freshmen at State University will eventually graduate. Suppose we take a random sample of n=81 new freshmen at State University. Let X = the number of these freshmen who eventually graduate. (Do not use a normal approximation for this problem. This is a binomial problem.) a) What is the probability that X < 45? b) What is the probability that 40 ≤ x ≤ 50? c) What is the probability that X = 48? d) What is the expected value of X? e) What is the variance of X? f) Copy your R script for the above into the text box here.
Transcribed Image Text:It is known that 45% of new freshmen at State University will eventually graduate. Suppose we take a random sample of n=81 new freshmen at State University. Let X = the number of these freshmen who eventually graduate. (Do not use a normal approximation for this problem. This is a binomial problem.) a) What is the probability that X < 45? b) What is the probability that 40 ≤ x ≤ 50? c) What is the probability that X = 48? d) What is the expected value of X? e) What is the variance of X? f) Copy your R script for the above into the text box here.
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