Building a Probability Model
Aligned to 7.SP.C.7 — Common Core State Standards for Mathematics.
What this lesson teaches
A probability model lists the possible outcomes and each outcome's probability, and all probabilities add to 1. In a uniform model every outcome is equally likely; otherwise you use observed data.
Worked example
A fair number cube has outcomes 1–6, each with probability 1/6. P(a number greater than 4) = P(5) + P(6) = 1/6 + 1/6 = 2/6 = 1/3.
Practice questions
- A fair coin is flipped. List the model and give P(tails).
- A spinner has 4 equal sections: red, blue, green, yellow. Find P(not red).
- A fair die is rolled. Find P(an even number).
Watch the lesson
Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.
▶ Watch this lessonEn español
Construir un Modelo de Probabilidad
Un modelo de probabilidad lista los resultados posibles y la probabilidad de cada uno, y todas las probabilidades suman 1. En un modelo uniforme cada resultado es igualmente probable; si no, usas datos observados.
Ejemplo: Un dado justo tiene los resultados 1–6, cada uno con probabilidad 1/6. P(un número mayor que 4) = P(5) + P(6) = 1/6 + 1/6 = 2/6 = 1/3.
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