Worked example 2 Aisling is at a carnival and sees a game which involves a spinner. The spinner she will play is shown and all sectors are equal in size. The game seems fair, so Aisling decides to play. (i) Looking at the spinner, fi nd the probability of Aisling: (a) winning
(b) losing (ii) Do you think Aisling is right to assume that this is a fair game?
(iii) Aisling plays the game fi ve times and does not win at all. Aisling now thinks the game is biased. Is she correct? Justify your answer.
(iv) Aisling doesn’t play any more games but she watches 40 other people play the game and only fi ve people win a prize. She is now convinced the game is biased. Is she correct? Justify your answer.
Solution (i)
(a)
(ii) (iii) (iv)
Relative frequency = the total number of trials ____________________ number of successful trials (b)