Statistics Basics :chart_with_upwards_trend: (Conditional Probability (Key…
Statistics Basics :chart_with_upwards_trend:
Positivley correlated variables
: When one irascible increases, the other variable increases.
Negatively correlated variables
: when one variable increase, the other variable decreases.
dependant/ response variable
: What is plotted on the x axis.
independent / explanatory variable
: what is plotted on the y axis.
: data has pairs of values for two variables.
: When one event has no effect on the other event. The probability of an independent event occurring is the product of all the events. :cow: :fire:
: An event that can have one outcome or the other, but never both. Mutually exclusive events
. :rain_cloud: :icecream:
Complement of A
: represents all the events where A does not occur.
Union of A and B
: Where A or B or both can occur.
Intersection of A and B
: only A and B can occur.
: A set pf possible outcomes.
: A collection of one or more outcomes.
: any repeatable process that gives outcomes.
P(A and B) = P(A) × P(B)
There are 2 ways of representing probability
Union, A ∪ B.
Remember u for
Complement of A, A'
Intersection, A ∩ B.
Remember n for
othig else can occur.
Tree diagrams :palm_tree:
"Two events are said to be mutually exclusive, when their occurrence is not simultaneous. Two events are said to be independent, when the occurrence of one event cannot control the occurrence of other."
vertical lines represent conditional probabilities (for outcomes in a restricted sample space)
P(A|B) or P(B|A)
The probability that B occurs given that A has already occurred.
Independent events; the probability of B occurring given that A has not occurred.
Independent events; the probability of A occurring given that B has not occurred.
Probability formulas to learn
Probability of union formula
P(A U B)= P(A) + P(B) - P(A n B)
Probability of intersection formula
P(B n A) = P(B|A) x P(A)
As P(B|A) = P(BnA) / P(A)