Exercise · ZW-PROBABILITY-MASS-FUNCTION-001 · ★☆☆ Basic
A variable \(X\) takes the values 0, 1 and 2 with \(p(0)=0.2\), \(p(1)=c\) and \(p(2)=0.5\). What is \(c\)?
Choose one option.
Show answer
- C. 0.3
Explanation
The masses add up to 1: \(0.2+c+0.5=1\), so \(c=0.3\).
Review the concept: Probability mass function
The probability mass function \(p_X\) of a discrete random variable \(X\) gives, for each value \(x\) it can take, the probability \(P\) that it takes it.
\[p_X(x)=P(X=x)\]
More practice problems: probability mass function
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