Probability

Probability, in the simplest sense, measures how likely an event is to happen. It's a foundational concept in mathematics and statistics, often represented as a value between 0 and 1—where 0 means the event is impossible, and 1 means it's certain. For example, flipping a fair coin has a probability of 0.5 (or 50%) for landing heads or tails.

Key Concepts of Probability:

1. Classical Probability: Assumes all outcomes are equally likely, such as rolling a fair six-sided die (each side has a probability of 1/6).

2. Frequentist Probability: Looks at the long-term frequency of an event occurring after many repetitions.

3. Subjective Probability: Based on personal judgment or belief, such as estimating the probability of rain tomorrow.

確率（Probability）は、ある事象が起きる可能性の度合いを示すものです。0から1の間で表され、0は「絶対に起きない」、1は「確実に起きる」を意味します。例えば、公正なコインを投げたとき、表が出る確率は50％、つまり0.5ですね。

確率の種類：

1. 古典的確率: 全ての結果が等しく起こりやすいと仮定する方法（例: サイコロの目の確率）。

2. 頻度主義確率: 何度も試行を繰り返した結果から得られる頻度に基づく確率。

3. 主観確率: 個人の信念や判断に基づく確率。

 

2025.8.18 copilot

https://irineko.hatenablog.com/entry/2025/08/18/203600