find the variance of the probability distribution for the histogram shown.

find the variance of the probability distribution for the histogram shown.

find the variance of the probability distribution for the histogram shown.

Answer

Explanation:

Step1: Identify probabilities from the histogram

The probabilities $P(x)$ for $x = 1, 2, \dots, 8$ are: $P(1)=0.1, P(2)=0.1, P(3)=0.15, P(4)=0.15, P(5)=0.05, P(6)=0.2, P(7)=0.1, P(8)=0.15$.

Step2: Calculate the expected value $\mu$

$\mu = \sum x \cdot P(x)$ $\mu = (1 \cdot 0.1) + (2 \cdot 0.1) + (3 \cdot 0.15) + (4 \cdot 0.15) + (5 \cdot 0.05) + (6 \cdot 0.2) + (7 \cdot 0.1) + (8 \cdot 0.15) = 4.7$

Step3: Calculate the expected value of $x^2$

$E[X^2] = \sum x^2 \cdot P(x)$ $E[X^2] = (1^2 \cdot 0.1) + (2^2 \cdot 0.1) + (3^2 \cdot 0.15) + (4^2 \cdot 0.15) + (5^2 \cdot 0.05) + (6^2 \cdot 0.2) + (7^2 \cdot 0.1) + (8^2 \cdot 0.15) = 26.8$

Step4: Calculate the variance $\sigma^2$

$\sigma^2 = E[X^2] - \mu^2$ $\sigma^2 = 26.8 - (4.7)^2 = 26.8 - 22.09 = 4.71$

Answer:

4.71