$\text { Find } \mathrm { f } _ { \mathbf { x } } , \mathrm { f } _ { \mathbf { y } } \text {, and } \mathrm { f } _ { \mathbf { Z } }$

question 377

Multiple Choice

$\text { Find } \mathrm { f } _ { \mathbf { x } } , \mathrm { f } _ { \mathbf { y } } \text {, and } \mathrm { f } _ { \mathbf { Z } }$
- $f ( x , y , z ) = x z \sqrt { x + y }$

• A) \(f _ { x } = z \left( \sqrt { x + y } - \frac { x } { 2 \sqrt { x + y } } \right) ; f _ { y } = - \frac { x y } { 2 \sqrt { x + y } } ; f _ { z } = x \sqrt { x + y }\)
• B) \(f _ { x } = z \left( \sqrt { x + y } - \frac { x } { \sqrt { x + y } } \right) ; f _ { y } = - \frac { x y } { \sqrt { x + y } } ; f _ { z } = x \sqrt { x + y }\)
• C) \(f _ { x } = z \left( \sqrt { x + y } + \frac { x } { \sqrt { x + y } } \right) ; f _ { y } = \frac { x z } { \sqrt { x + y } } ; f _ { z } = x \sqrt { x + y }\)
• D) \(f _ { X } = z \left( \sqrt { x + y } + \frac { x } { 2 \sqrt { x + y } } \right) ; f _ { y } = \frac { x z } { 2 \sqrt { x + y } } ; f _ { z } = x \sqrt { x + y }\)

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Definitions:

Ages

A term referring to the different stages of life or periods in history, often used in the study of human development or demographics.

Selective Attrition

The process by which participants drop out of a study over time, not randomly, potentially biasing the results.

Cross-Sectional Study

This observational research approach evaluates information from either an entire population or a sample that reflects it, focusing on a singular time frame.

Longitudinal Study

A research design that involves repeated observations of the same variables (e.g., people) over short or long periods of time, often years or even decades.