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Discrete Variable
quantitative variable that has either a finite number of possible values or a countable number of possible values. The term countable means that the values result from counting, 1,2,3. A discrete variable cannot take on every possible value between any teo possible values.
Examples: # of Baseball Games won by the Cardinals , # of members of a family, # of students in a class, # of leaves on a tree, # of digits in a zip code, # of stars in the galaxy, # of people who wear glasses, etc.
Continuous Variable
quantitative variable that has an infinite number of possible values that are not countable. A continuous variable may take on every possible value between any two values.
Examples: a person's temperature, distance between two places, the speed of an object, time, amount of force applied, etc
Nominal level of measurement
if the values of the variable name, label, or categorize. In addition, the naming sceme does not allow for the values of the variable to be arranged in a ranked or specific order.
EX: Grouping people by their nationality, gender, their religion, zip code of residence, marital status, etc.
Ordinal level of measurement
if it has the properties of the nominal level of measurement, however the naming scheme allows for the values of the variable to be arranged in a ranked or specific order
Ex: Letter Grades ( A, B, C, D, & F); Rating Scales ( Outstanding, Excellent, Good, Average, Poor, Unsatisfactory); Rankings ( General, Colonel, Captain, Sergeant , Corporal, Private)
Interval level of measurement
if it has the properties of the ordinal level of measurement and the differences in the values of the variable have meaning. A value of zero foes not mean the absence of the quanitity. Arthmetic operations such as addition and subtraction can be performed on values of the variable.
EX: IQ may be 100 or 110 ( An IQ of zero does not exist), Temperature may be 90 or 91 degrees ( 0 temperature does not mean no heat)
Ratio level of measurement
if it has the properties of the interval level of measurement and the ratios of the values of the variable have meaning. A value of zero means the absence of the quantity. Arithmetic operations such as multiplication and division can be performed on the values of the varibale.
Ex: (Examples include height, weight, area, # of phone calls, etc.)
Random variable
is one whose values are determined by chance
Independent variable
is one whose value is chosen free of any influence by the value of other variables or any given situation
