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42 Cards in this Set
- Front
- Back
- way to map outcomes of statistical experiment determined by chance into a number |
Random variable |
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- set whose elements are the numbers assigned to the outcomes of an experiment - possible values of the rv x |
Sample space |
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2 types of probability distribution |
Discrete and continuous random variable |
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- type of probability distribution - countable - random variable that can take on finite number of distinct values |
Discrete rv |
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- type of probability distribution - measurable quantities - random variable that takes on infinite, countable number of possible values , typically measurable quantities |
Continuous rv |
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What type of random variable is this? Number of heads obtained when tossing a coin 3x |
Discrete rv |
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What type of probability distribution is this? Time a person can hold his or her breath |
Continuous rv |
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- consists of the values a random variable can assume and the corresponding probabilities |
Discrete probability distribution |
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- possible values of random variable is denoted by... |
X |
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- corresponding probability of a random variable is denoted by... |
P(X) -> probability of x (event) |
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- any activity whose results are unknown |
Random experiment |
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- number of times an event or result of occurs - how likely outcomes occur - how many times x comes out |
Frequency |
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- numerical quantity resulting from a random experiment |
Random variable |
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- number of elements in a set |
Cardinality |
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- by ratio, fraction, or decimal - the ratio of the rv and frequency Random variable/frequency |
Probability P(X) |
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- all outcomes are equally likely to occur - theoretical - used in experiments (tossing a coin -> theoretical) |
Classical probability |
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- uses frequency distribution - based on observation to determine numerical probability of event - in behavioral activity |
Empirical probability |
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- assigned to an event - based on subjective judgment, experience, info, and belief - used for testimonies |
Subjective probability |
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3 types of probability |
Classical, empirical, and subjective |
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- common scale factor (common na lumalabas na outcome) |
Mass point |
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How do you get the cardinality of a random experiment? |
Summation of frequency or number of events of a random experiment |
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P(X=x) is read as... |
Probability of random experiment resulting to random variable |
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- probability distribution of a discrete random variable described by a piece-wise function - denoted by f(x) |
Pmf or probability mass funtion |
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:if probability is in table, :if probability is in equation, |
:Probability distribution :Probability Mass function |
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Format of mass point |
1/sum total of F or cardinality So if total sum of F or cardinality is 12, 1/12 -> mass point |
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- graphical representation of the rv on the x-axis, and the probability of the rv on the y-axis - uses bars - like a bar graph but does not have spaces in between bars |
Probability histogram |
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- quick assessment to determine if the given rv is normally distributed |
Bell-curve or normal curve |
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2 properties of a probability distribution |
1. Σ P(X) = 1 -> must be equal to 1 2. 0 ≤ P(X) ≤ 1 -> must be positive (must satisfy both properties) |
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Formula for mean |
Σ xP(X) |
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Component of formula for variance |
Σ x²P(X) |
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Formula for variance and standard deviation |
σ² = Σx²P(X) - μ² σ = √(Σx²P(X) - μ²) |
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Similarity and difference between mean and expected value |
Similarity: formula -> Σ xP(X) Difference: •mean - to interpret the data in terms of average •expected value - to determine gains and losses in a random experiment |
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In expected value, if E(x) is positive/negative... |
Positive: gain Negative: lose |
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Difference of x̄ and μ (mean) |
x̄ - used for statistics (for samples) μ - used for parameter (for population) |
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Determine the mean [Σ xP(X)], variance (Σ x²P(X) - μ²), and standard deviation √Σx²P(X) - μ² X |10| 5 | 3 |2 P(X)|0.2|0.1|0.4|0.3 |
Σ xP(X) = 4.3 Σ x²P(X) = 27.3 Σ x²P(X) - μ² = √8.81 = 2.9681 |
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Determine the expected value. X | -500| 300| 500 P(X) | 0.3 | 0.5 | 0.2 |
E(X) = ₱100 |
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- total quantity of area |
z-score |
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If equation has 0, If </>, If ≤/≥, |
Go to z-score table Get approximate z-score Get the lesser/greater z-score |
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If same signs, If different signs, |
Subtract Add |
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3 characteristics of normal distribution |
1. Asymptotic 2. Symmetrical 3. Area is equal to 1 or 100% |
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x - μ - σ - x̄ - s - |
x - given measurement μ - population σ - standard deviation x̄ - sample data s - sample standard deviation |
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Formula if percentage was asked |
Instead of z= (x - x̄)/s x = z(s) + x̄ |