← Statistics for Data Science learning pathStatistics for Data Science · Module 3 of 10
Probability basics
Measure uncertainty with probability.
📖 Key ideas
- Probability ranges from 0 (impossible) to 1 (certain).
- P(A) = favourable outcomes / total outcomes (for equally likely outcomes).
- Independent events: P(A and B) = P(A) × P(B).
- P(A or B) = P(A) + P(B) − P(A and B).
- Conditional probability: P(A|B) = P(A and B) / P(B).
💡 Real-life example: Probability is the weather forecast's "70% chance of rain" applied to any event.
ProbabilityChance of an event, 0 to 1
Independent eventsOne does not affect the other
Conditional probabilityProbability given another event
ComplementP(not A) = 1 − P(A)