Ms Taylor sets her class a test of 48 multiple-choice questions, each with four options A-D. Let the random variable X be the number of questions a person gets correct. a Calculate the expected value E (X). How can this value be understood in this context? b What is the standard deviation of the random variable? c Ms Taylor is annoyed to discover that Fayola, one of her students, claims to have got 24 just by guessing. How many standard deviations is Fayola's score above the mean? Ms Taylor writes a new test, with 100 questions, each with five options A-E. d What is the expected value and standard deviation of this new distribution with random variable Y? Fayola gets 40 questions right this time, and again she claims to have achieved this result just by guessing. If true, would this be more or less unusual than her previous result? e f Idette gets 75% in the first test and 60% in the second. Which is the more unusual of her results, if she is guessing?

Ms Taylor sets her class a test of 48 multiple-choice questions, each with four options A-D. Let the random variable X be the number of questions a person gets correct. a Calculate the expected value E (X). How can this value be understood in this context? b What is the standard deviation of the random variable? c Ms Taylor is annoyed to discover that Fayola, one of her students, claims to have got 24 just by guessing. How many standard deviations is Fayola's score above the mean? Ms Taylor writes a new test, with 100 questions, each with five options A-E. d What is the expected value and standard deviation of this new distribution with random variable Y? Fayola gets 40 questions right this time, and again she claims to have achieved this result just by guessing. If true, would this be more or less unusual than her previous result? e f Idette gets 75% in the first test and 60% in the second. Which is the more unusual of her results, if she is guessing?

Glencoe Algebra 1, Student Edition, 9780079039897, 0079039898, 2018

18th Edition

ISBN:9780079039897

Author:Carter

Publisher:Carter

Chapter10: Statistics

Section10.4: Distributions Of Data

Problem 19PFA

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