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Question
Choose the correct alternative:
The probability mass function of a random variable is defined as:
| x | – 2 | – 1 | 0 | 1 | 2 |
| f(x) | k | 2k | 3k | 4k | 5k |
Then E(X ) is equal to:
Options
`1/15`
`1/10`
`1/3`
`2/3`
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Solution
`2/3`
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