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A random variable $$X$$ has the following probability distribution:
| $$X$$ | 0 | 1 | 2 | 3 | 4 |
| $$P(X)$$ | $$k$$ | $$2k$$ | $$4k$$ | $$6k$$ | $$8k$$ |
We are given a random variable $$X$$ with the probability distribution:
$$P(X=0) = k, \quad P(X=1) = 2k, \quad P(X=2) = 4k, \quad P(X=3) = 6k, \quad P(X=4) = 8k$$
Since the total probability must equal 1:
$$k + 2k + 4k + 6k + 8k = 1$$
$$21k = 1$$, so $$k = \frac{1}{21}$$
We need to find $$P\left(\frac{1 < X < 4}{X \leq 2}\right)$$, which is the conditional probability $$P(1 < X < 4 \mid X \leq 2)$$.
The event $$\{1 < X < 4\} = \{X = 2, X = 3\}$$
The event $$\{X \leq 2\} = \{X = 0, X = 1, X = 2\}$$
The intersection $$\{1 < X < 4\} \cap \{X \leq 2\} = \{X = 2\}$$
$$P(X = 2) = 4k = \frac{4}{21}$$
$$P(X \leq 2) = k + 2k + 4k = 7k = \frac{7}{21} = \frac{1}{3}$$
Therefore:
$$P(1 < X < 4 \mid X \leq 2) = \frac{P(\{1 < X < 4\} \cap \{X \leq 2\})}{P(X \leq 2)} = \frac{4/21}{7/21} = \frac{4}{7}$$
The correct answer is Option A.
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