Discover a wealth of information and get your questions answered on IDNLearn.com. Our platform provides trustworthy answers to help you make informed decisions quickly and easily.

Use the probability distribution for the random variable x to answer the question. x 0 1 2 3 4 p(x) 0.12 0.2 0.2 0.36 0.12 Calculate the population mean, variance, and standard deviation. (Round your standard deviation to three decimal places.)

Sagot :

Answer:

[tex]\mu =2.16[/tex] --- Mean

[tex]\sigma^2 = 1.4944[/tex] -- Variance

[tex]\sigma = 1.222[/tex] --- Standard deviation

Step-by-step explanation:

Given

[tex]\begin{array}{cccccc}x & {0} & {1} & {2} & {3} & {4} \ \\ P(x) & {0.12} & {0.2} & {0.2} & {0.36} & {0.12} \ \end{array}[/tex]

Solving (a): The population mean

This is calculated as:

[tex]\mu = \sum x * P(x)[/tex]

So, we have:

[tex]\mu =0*0.12 + 1 * 0.2 + 2 * 0.2 + 3 * 0.36 + 4 * 0.12[/tex]

[tex]\mu =2.16[/tex]

Solving (b): The population variance

First, calculate:

[tex]E(x^2)[/tex] using:

[tex]E(x^2) = \sum x^2 * P(x)[/tex]

So, we have:

[tex]E(x^2) = 0^2*0.12 + 1^2 * 0.2 + 2^2 * 0.2 + 3^2 * 0.36 + 4^2 * 0.12[/tex]

[tex]E(x^2) =6.160[/tex]

So, the population variance is:

[tex]\sigma^2 = E(x^2) - \mu^2[/tex]

[tex]\sigma^2 = 6.16 - 2.160^2[/tex]

[tex]\sigma^2 = 6.160 - 4.6656[/tex]

[tex]\sigma^2 = 1.4944[/tex]

Solving (c): The population standard deviation

This is calculated as:

[tex]\sigma = \sqrt{\sigma^2}[/tex]

[tex]\sigma = \sqrt{1.4944}[/tex]

[tex]\sigma = 1.222[/tex]