Chapters 1-4 Flashcards
Population
Defined collection or group of objects
Census
Data is available for all objects in population
Sample
Subset of population
Variable
Any characteristic whose value may change from one object to another in the population
Empirical Data
Based on observation
Frequency
Number of times that a data value occurs in the data set
Relative Frequency
A proportion of time that the value occurs
Unimodal
1 peak
Bimodal
2 peaks
Multimodal
More than 2 peaks
Symmetric
Mirror image
Positively Skewed
Right stretched
Negatively Skewed
Left Stretched
Uniform
Straight
Truncated
Limited
Mode
Most frequent value that occurs in a data set
Quartiles
Divides data into four equal parts
Trimmed Means
Mean obtained form trimming off a% of the observations from “each” side of a data set
Range
Difference between the largest and smallest values
Standard Deviation
Square root of the average squared deviation from the mean
Variance
Square of the standard deviation
Event
Subset of outcomes contained in the sample space
Simple Event
Consists of exactly one outcome
Compound Event
Consists of more than one outcome
Union
A or B
Intersection
A and B
Complement
A’
Mutually Exclusive
No outcomes in common
Permutation
An ordered arrangement of k distinct objects taken from a set of n distinct objects
Combination
An unordered arrangement of k distinct objects taken from a set of n distinct objects
Random Variable
A “rule” that assigns a number to each outcome in the sample space
Discrete
Possible values either constitute a finite set or else an infinite sequence in which there is a first element, second element, etc.
Continuous
Possible values consists of an entire interval on the number line
Bernoulli RV
A random variable with two possible outcomes: 0 or 1
Probability Distribution
A mathematical model that relates the value of a random variable with the probability of occurrence of that value in the population
