Example: Northwestern University posts the grade distribution for its courses online. Students in Statistics 101 in a recent semester received 26% A’s, 42% B's, 20% C's, 10% D’s, and 2% F's. Choose a Statistics 101 student at random. The student's grade on a four point scale (with A = 4) is a discrete random variable X with this probability distribution: 1. Say in words what the meaning of P(X23) is. What is this probability? 2. Write the event “the student got a grade worse than C" in terms of values of the random variable X. What is the probability of this event? 3. Compute the mean of the random variable X. Interpret this value in context. Discrete Random Variable: Variance/Standard Deviation The standard deviation of a random variable X is a measure of how much the values of the variable typically vary from the expected value. X P(X)

Example: Northwestern University posts the grade distribution for its courses online. Students in Statistics 101 in a recent semester received 26% A’s, 42% B's, 20% C's, 10% D’s, and 2% F's. Choose a Statistics 101 student at random. The student's grade on a four point scale (with A = 4) is a discrete random variable X with this probability distribution: 1. Say in words what the meaning of P(X23) is. What is this probability? 2. Write the event “the student got a grade worse than C" in terms of values of the random variable X. What is the probability of this event? 3. Compute the mean of the random variable X. Interpret this value in context. Discrete Random Variable: Variance/Standard Deviation The standard deviation of a random variable X is a measure of how much the values of the variable typically vary from the expected value. X P(X)

College Algebra

10th Edition

ISBN:9781337282291

Author:Ron Larson

Publisher:Ron Larson

Chapter8: Sequences, Series,and Probability

Section8.7: Probability

Problem 50E: Flexible Work Hours In a recent survey, people were asked whether they would prefer to work flexible...

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