Very scared. Scared of scary doggo.
The entity integrity rule states that a primary key attribute can be null. Thus the statement is false.
<h3>What is an entity?</h3>
An entity is refer to any object that exists in reality. These entities are Independent in nature. Each row in a table should be a distinct entity, which is ensured by entity integrity.
The entity integrity rule states that a primary key attribute can not be null as it shows unique characteristics of an entity.No primary key value can be null according to the entity integrity constraint because it is needed to identify specific attribute values in relation.
Therefore, the statement is False.
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Answer:
75%
Explanation:
In order to understand this question you need to understand the matching law first. The matching law provides the density of reinforcement or the rate of reinforcement if more than one response is available simultaneously to the individual. Here, two responses are available which are left key, 60 reinforcers per hour, and right key, 20 reinforcers per hour. This provides the ratio between the two reinforcers which is 60:20 or 3:1 in favor of left key. Here, one has to make a prediction only for left key and based on 3:1 ratio it can be said that 75% of pigeon will make their responses on the left key.