In: Statistics and Probability
Compute the mean and variance of the following probability distribution.
x P(x)
5................................. .1
10............................... .3
15............................... .2
20............................... .4
X |
P(X) |
X * P(X) |
X2 * P(X) |
5 |
0.1 |
0.5 |
2.5 |
10 |
0.3 |
3 |
30 |
15 |
0.2 |
3 |
45 |
20 |
0.4 |
8 |
160 |
ΣX × P(X) = 14.5 |
ΣX2 × P(X) = 237.5 |
Expected value of X is,
E(X) = ΣX × P(X) = 14.5
Variance of X is,
Var(X) = ΣX2 × P(X) – [E(X)]2 = 237.5 – [14.5]2 = 27.25
Therefore, Mean and variance of the given probability distribution are,
Mean = 14.5
Variance = 27.25
Therefore, Mean and variance of the given probability distribution are,
Mean = 14.5
Variance = 27.25