# GCSE Statistics Chapter 7 Summary- Probability

After completing this chapter, you will be able to;

- Understand the meanings of the words ‘event’ and ‘outcome’
- Use a likelihood scale
- Put outcomes in order in terms of probability
- Put probabilities in order on a probability scale
- Understand the terms ‘random’, ‘equally likely’, ‘mutually exclusive’ and ‘exhaustive’.
- Understand and use measure of probability from a theoretical perspective and from a limiting frequency or experimental approach
- Compare expected frequencies and actual frequencies
- Use simulation to estimate more complex probabilities
- Use probability to assess risks
- Produce, understand and use a sample space
- Understand and use the addition and multiplication laws
- Use and calculate conditional probabilities
- Draw and use probabilities tree diagrams.

- Created by: Lottie_Anderson
- Created on: 08-12-12 12:30

First 242 words of the document:

Events and outcome

1.) A trial is the act of testing/ doing something.

2.) Outcomes are the possible results of a trial.

3.) An event is a set of one or more successful outcomes.

The meaning of probability

4.) Probability is a numerical measure of the chance of an event happening.

A probability of 0 means it is impossible for the event to happen

A probability of 1 means the event is certain to happen

5.) Probabilities can be written as fractions, decimals or percentages.

6.) When something is chosen at random, it means it is selected without a

conscious choice.

7.) When outcomes have the same chance of happening they are called equally

likely outcomes.

The probability of an event

8.) If all possible outcomes are equally likely, the probability of an event

=number of successful outcomes/total number of possible outcomes

Experimental probability

9.) The estimated probability that an event might happen

=number of successful outcomes/total number of trials

10.) As the number of trials increase in experiments and surveys the nearer an

estimate for the probability should be to the true value.

11.) Simulation is the imitation of the conditions of a situation by a theoretical

study.

12.) Cost of risk insurance= money at risk x risk assessment (p)

Sample space

13.) A list of all possible outcomes is called a sample space.

Venn diagrams

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