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Multiplication rule

The multiplication rule determines a combined count or probability by multiplying the numbers of choices or the relevant probabilities at successive stages.

How 2 Manning books explain it

Statistics Every Programmer Needs

The multiplication rule of counting determines the number of outcomes formed by successive choices by multiplying the numbers of options at each stage.

How it is used
Counts combined outcomes and supplies success and total-outcome counts for theoretical probabilities.
How deep it goes
Defines the product formula, works through dice and repeated-position counts, and flags independent choices and changing options.
Examples
Uses ordered dice rolls, license plates, three-digit locks, and a Python calculation of 5³ = 125.
What you can do after
Apply it to count combined outcomes and calculate probabilities from successful and total outcome counts.

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Grokking Machine Learning

A rule stating that the probability of independent events occurring together equals the product of their individual probabilities.

How it is used
Uses joint probabilities to calculate spam-detection probabilities from email features.
How deep it goes
Works through conditional probabilities with an email tree and applies independence to estimate joint word probabilities.
Examples
Calculates email probabilities using spam, ham, and the words “lottery” and “sale.”
What you can do after
Evaluate joint email probabilities and estimate them using an independence assumption.

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Related concepts

These guides are generated from the text of Manning books by Manning's knowledge graph and link to the sections they draw on. The full books are available on liveBook and at manning.com.