Stratified Sampling May Be Used When

question 41

Multiple Choice

Stratified sampling may be used when

• A)subgroups that are representative of the whole population can be identified.
• B)natural subgroups are more homogeneous than the population they come from.
• C)an expert is available to identify a representative population.
• D)the sample is very small.
• E)none of the above.

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Definitions:

Rotor Speed

The rotational speed of the rotor in a motor or generator, typically measured in revolutions per minute (RPM).

Percent Slip

In an induction motor, the difference between the synchronous speed and the actual rotor speed, expressed as a percentage of the synchronous speed.

Three-Phase Motor

An electric motor that operates on three phases of alternating current, offering smoother and more efficient operation than single-phase motors for high-power applications.

Direction of Rotation

The direction in which a mechanical or electrical device rotates, which can be clockwise or counterclockwise.