During lunch, all 240 students flipped 3 coins. How many students would you expect to get exactly 1 tails?

Chapsterj asked Dec 15, 2023

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Chapsterj asked Dec 15, 2023

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30 votes

Solution

The probability of getting exactly 1 tail from three coins is

$\begin{gathered} THH,HTH,HHT \\ \\ p=(3)/(2^3) \\ \\ p=(3)/(8) \end{gathered}$

The expected value will be

$\begin{gathered} E(X)=240*(3)/(8) \\ \\ E(X)=90 \end{gathered}$

The answer is 90 students

Jeff Huijsmans answered Dec 19, 2023

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