1. Probability 1 4 2 6 8 9 3 5 7 1 Vocabulary:
probability sample space chance
likelihood certain likely
equally likely unlikely event
outcome experiment theoretical
spinner die dice
favourable fair bias
random complement 2 6 8 9 3 5 7 1

2. What is Probability?
Probability is the study of chance, or how likely something is to happen. Probabilities range from 0 (an impossible event) to 1 (a certain event). If things have an equal chance of happening, we call them equally likely outcomes. This continuum shows where probabilities fall:
On the continuum, place in the correct positions:
likely unlikely very unlikely certain
Impossible very likely equally likely 2 5 4 11 13 3 6 10 14 1 15 8 7 9 12

8. Sample Space
The sample space is a list of all possible outcomes. For a coin, we say the sample space is {heads, tails}, because there is no other possible outcome. 2 5 4 11 13 3 6 10 14 1 15 8 7 9 12

10. 2 5 4 3 6 1 8 7 9 Theoretical Probability
A pail contains eight red marbles, five blue marbles, six green marbles and three yellow marbles. If a single marble is chosen from the pail, what is the probability it will be red? Blue? Green?
𝑃 𝑅𝑒𝑑 = 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑟𝑒𝑑 𝑚𝑎𝑟𝑏𝑙𝑒𝑠 𝑡𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑚𝑎𝑟𝑏𝑙𝑒𝑠
= 8 22
𝑃 𝐵𝑙𝑢𝑒 = 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑏𝑙𝑢𝑒 𝑚𝑎𝑟𝑏𝑙𝑒𝑠 𝑡𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑚𝑎𝑟𝑏𝑙𝑒𝑠 =
𝑃 𝐺𝑟𝑒𝑒𝑛 = 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑔𝑟𝑒𝑒𝑛 𝑚𝑎𝑟𝑏𝑙𝑒𝑠 𝑡𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑚𝑎𝑟𝑏𝑙𝑒𝑠 2 5 4 11 13 3 6 10 14 1 15 8 7 9 12

17. The complement
The sum of the probabilities of all possible outcomes of a simple event is always 1. This can be used to simplify calculations (it is called using the complement). 2 5 4 11 13 3 6 10 14 1 15 8 7 9 12