Math Problem Statement

​(b) Compute the mean and standard deviation of the random variable using

mu Subscript Upper XμXequals=Summation from nothing to nothing left bracket x times Upper P left parenthesis x right parenthesis right bracket∑[x•P(x)]

and

sigma Subscript Upper XσXequals=StartRoot Summation from nothing to nothing left bracket x squared times Upper P left parenthesis x right parenthesis right bracket minus mu Subscript Upper X Superscript 2 EndRoot∑x2•P(x)−μ2X.

mu Subscript Upper XμXequals=enter your response here

​(Round to two decimal places as​ needed.)

Solution

To calculate the mean μX\mu_X and standard deviation σX\sigma_X of a discrete random variable, we use the following formulas:

1. Mean (μX\mu_X):

μX=[xP(x)]\mu_X = \sum [x \cdot P(x)] This means we take each value xx, multiply it by its corresponding probability P(x)P(x), and then sum these products.

2. Standard Deviation (σX\sigma_X):

σX=[x2P(x)]μX2\sigma_X = \sqrt{ \sum [x^2 \cdot P(x)] - \mu_X^2 } This requires first calculating [x2P(x)]\sum [x^2 \cdot P(x)] and then subtracting the square of the mean, μX2\mu_X^2, from it. Finally, take the square root to find σX\sigma_X.

Steps to compute:

  1. List the values of xx and their corresponding probabilities P(x)P(x).
  2. Compute [xP(x)]\sum [x \cdot P(x)] to find the mean μX\mu_X.
  3. Compute [x2P(x)]\sum [x^2 \cdot P(x)].
  4. Plug these into the formula for σX\sigma_X and compute the standard deviation.

Please provide the values of xx and P(x)P(x) so I can help you compute the mean and standard deviation.

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Math Problem Analysis

Mathematical Concepts

Probability
Statistics
Random Variables

Formulas

Mean (μX) = ∑[x•P(x)]
Standard Deviation (σX) = √[∑[x²•P(x)] - μX²]

Theorems

Law of Expected Value
Variance and Standard Deviation Theorem

Suitable Grade Level

Grades 10-12