COMEDK · Maths · 36. Probability
The probability distribution of a discrete random variable X is given as
| X | 1 | 2 | 4 | 2A | 3A | 5A |
|---|---|---|---|---|---|---|
| P(X) | \(\dfrac{1}{2}\) | \(\dfrac{1}{5}\) | \(\dfrac{3}{25}\) | K | \(\dfrac{1}{25}\) | \(\dfrac{1}{25}\) |
\(\text { Then the value of } A \text { if } E(X)=2.94 \text { is }\)
- A \(\dfrac{1}{2}\)
- B \(\dfrac{1}{3}\)
- C 2
- D 3
Answer & Solution
Correct Answer
(D) 3
Step-by-step Solution
Detailed explanation
The sum of probabilities in a probability distribution is equal to 1. \(\dfrac{1}{2} + \dfrac{1}{5} + \dfrac{3}{25} + K + \dfrac{1}{25} + \dfrac{1}{25} = 1\) \(\dfrac{25 + 10 + 6 + 2 + 2}{50} + K = 1\) \(\dfrac{45}{50} + K = 1 \Rightarrow K = 1 - \dfrac{9}{10} = \dfrac{1}{10}\)…
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