What Is the Average Central-Ray Angulation for the PA Axial

question 3

Multiple Choice

What is the average central-ray angulation for the PA axial (Haas) projection of the skull?

• A) 25 degrees caudad
• B) 25 degrees cephalad
• C) 30 degrees caudad
• D) 30 degrees cephalad

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Definitions:

Dependent Variable

In an experiment or model, it is the variable being tested and measured, which is expected to change as a result of changes in the independent variable(s).

Independent Variable

A variable in an experiment or statistical model that is manipulated or controlled by the experimenter to observe its effect on a dependent variable.

SSE

Sum of Squared Errors; a measure of the discrepancy between the data and an estimation model.

SST

Sum of Squared Total, a measure used in statistics to quantify the variance within a set of observations.