1 - Intro & Probability Flashcards
What’s the difference between probability and statistics?
Probability deals with predicting the likelihood of future events, while statistics involves the analysis of the frequency of past events
What’s the difference between the frequentist and Bayesian approaches to statics?
The frequentist approach uses fixed parameters and tells you the probability that you would obtain the same outcome if you replicate the same conditions again.
The Bayesian approach does not have fixed parameters and takes unknown factors into consideration while making guesses based on observations to draw conclusions.
What are elementary events?
A set of elements such that for a given observation, the outcome will be one and only one of these events.
AKA. contain a single outcome in the sample space
What is a sample space?
The set of total possible events.
What is the sum of the probabilities of the outcomes in a sample space?
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What are non-elementary events?
A set of elements such that for a given observation, the outcome will be a subset that contains more than 1 element.
Ex. {blue jeans, black jeans, grey jeans}
What is a binomial distribution?
A discrete probability distribution for which there are 2 possible outcomes (success/ failure) with fixed probabilities summing to 1.
Important: the 2 possible outcomes must be independent of each other
What is another name for a normal distribution?
Bell Curve of Gaussian Distribution
What is a normal distribution?
A continuous probability distribution that is symmetrical on both sides of the mean. Can be described in terms of the mean and standard deviation.
What must the area under the curve of a normal distribution sum up to?
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What is a t-distribution?
A type of normal distribution used for smaller sample sizes, where the variance in the data is unknown. Used for smaller samples.
What is a chi-squared distribution?
Test that tells you whether the frequencies of the levels of a categorical variable are significantly different from the expected frequencies under a certain probability distribution.
What is an f distribution?
A distribution that defines the ratio of the variances of the two normally distributed populations.
