Maths Interactives
General
Methods
Specialist
·
Unit 1
Unit 2
Unit 3
Unit 4
Recent
Random
About
Review
Compare
Inbox
Home
·
Unit 4
· Topic 3
Topic 3: Continuous random variables and the normal distribution
General continuous random variables
6 hours
Use relative frequencies and histograms obtained from data to estimate probabilities associated with a continuous random variable.
Understand the concepts of a probability density function, cumulative distribution function, and probabilities associated with a continuous random variable given by integrals; examine simple types of continuous random variables and use them in appropriate contexts.
1 interactive
Calculate the expected value, 𝐸 (𝑋) = 𝜇 = ∫ 𝑥𝑝(𝑥)𝑑𝑥 ∞ −∞, of a continuous random variable where 𝑝(𝑥) is the probability density function.
1 interactive
Calculate the variance, 𝑉𝑎𝑟(𝑋) = 𝜎 2 = ∫ (𝑥 − 𝜇)∞ −∞ 2 𝑝(𝑥)𝑑𝑥, and standard deviation 𝜎, of a continuous random variable.
Understand standardised normal variables (𝑧-values, 𝑧-scores) and use these to compare samples.
1 interactive
Normal distributions
6 hours
Identify contexts, e.g. naturally occurring variations, that are suitable for modelling by normal random variables.
Recognise features of the graph of the probability density function of the normal distribution with mean 𝜇 and standard deviation 𝜎 and the use of the standard normal distribution.
1 interactive
Recognise and use the link between the normal distribution and the notation 𝑋 ∼ 𝑁(𝜇, 𝜎 2).
Calculate probabilities and quantiles associated with a given normal distribution, using technology.
Model and solve problems that involve normal distributions, with and without technology (distribution tables are not required).