A t-test can be used to account for the uncertainty in the sample variance when the sample size is small and the data are exactly normal. There is no universal constant at which the sample size is generally considered large enough to justify use of the plug-in test. Typical rules of thumb range from 20 to 50 samples.
Each symbol and color in the National Law Enforcement Explorers seal has special significance. 1  The circular form of the seal represents continuous existence. 2  The dominant blue field represents justice. 3  The inner circle contains a shield surmounted by an eagle.
Color of law refers to an appearance of legal power to act but which may operate in violation of law. For example, though a police officer acts with the color of law authority to arrest someone, if such an arrest is made without probable cause the arrest may actually be in violation of law.