Which of the Following Formulas Will Compute the Variance of a Discrete

question 43

Multiple Choice

Which of the following formulas will compute the variance of a discrete random variable X?

• A)\(\sum_{j=1}^{n}\left(x_{j}-E[X]^{2}\right)\)
• B)\(\sum_{j=1}^{\infty} \mathrm{E}[X]^{2} f\left(x_{j}\right)\)
• C)\(\sum_{j=1}^{\infty}\left(x_{j}-E[X]\right)^{2} f\left(x_{j}\right)\)
• D)\(\sum_{j=1}^{\infty}\left(x_{j}\right) 2 f\left(x_{j}\right)\)

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Definitions:

Cell Membrane

The semipermeable membrane surrounding the cytoplasm of a cell, which controls the entry and exit of substances.

Phospholipids

A type of fat molecule that forms the main structural component of cell membranes.

Cholesterol

A type of lipid molecule that is crucial for the formation of cell membranes and serves as a precursor for the synthesis of certain hormones and vitamins.

Steroid

A type of organic molecule with a characteristic structure consisting of four fused rings, playing various roles in the body including as components of cell membranes and as signaling molecules.