A Veterinarian Interested in Studying the Causes of Enteroliths in Horses

question 21

Multiple Choice

A veterinarian interested in studying the causes of enteroliths in horses suspects that a diet high in alfalfa may be a cause. The veterinarian decides to use the following design: identify 30 horses at high risk for enteroliths, and divide them into 10 groups of 3 horses. Some groups consist of horses in barn stalls, some groups consist of horses in outdoor paddocks, and some groups consist of horses in pastures. Within each group, one horse is randomly assigned to an alfalfa diet, one is assigned to a grass hay diet, and one horse is fed oat hay. When a horse is in a pasture, all the other horses in that pasture will also receive the diet of the study horse. Therefore, only one horse could be selected from a given pasture. This study has:

• A)one factor and three treatments.
• B)one treatment and three factors.
• C)three treatments and three factors.
• D)one factor and one treatment.

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Definitions:

Proportional Plus Derivative

A control method in feedback system design that uses a combination of the proportional and derivative actions to improve system response and stability.

PID

Proportional-Integral-Derivative closed-loop control that lets the user hold a process variable at a desired set-point.

Thermistor

A type of resistor whose resistance varies significantly with temperature, widely used as temperature sensors.