
To solve the problem, we need to compute the expected value \( E(X) \) of the given discrete probability distribution.
1. Use the Formula for Expected Value:
The expected value \( E(X) \) is given by:
\( E(X) = \sum [x_i \cdot P(x_i)] \)
2. Substitute the Given Values:
\[
E(X) = (-4)(0.1) + (-3)(0.2) + (-2)(0.3) + (-1)(0.2) + (0)(0.2)
\]
\[
= -0.4 + (-0.6) + (-0.6) + (-0.2) + 0
\]
\[
= -0.4 - 0.6 - 0.6 - 0.2 = -1.8
\]
3. Conclusion:
The expected value of the distribution is \( -1.8 \)
Final Answer:
The correct option is (A) -1.8.
If the probability distribution is given by:
| X | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
|---|---|---|---|---|---|---|---|---|
| P(x) | 0 | k | 2k | 2k | 3k | k² | 2k² | 7k² + k |
Then find: \( P(3 < x \leq 6) \)
If \(S=\{1,2,....,50\}\), two numbers \(\alpha\) and \(\beta\) are selected at random find the probability that product is divisible by 3 :
