Statistics Flashcards: Calculating Expected Value Of Random Variables

Study Calculating Expected Value Of Random Variables in Statistics with focused flashcards that help you recognize the idea, recall the key rule, and apply it in practice-style prompts.

QUESTION

Find and correct the formula error: E(X)=P(X=x)E(X)=\sum P(X=x).

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ANSWER

Correct: E(X)=xP(X=x)E(X)=\sum x\,P(X=x). Missing the multiplication by xx in each term.

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Statistics: Expected Value

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What this deck covers

This deck focuses on Calculating Expected Value Of Random Variables, giving you a quick way to review the definitions, rules, and examples that matter most for Statistics.

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Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Practice questions

1 of 26Practice questions for this set
A raffle ticket has the following net winnings (in dollars). Let XX be the net winnings from buying one ticket. P(X=2)=34P(X=-2)=\tfrac{3}{4} and P(X=6)=14P(X=6)=\tfrac{1}{4}. What is the expected value of XX (in dollars)? (Note: the expected value may not be a possible outcome.)
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