ZIMSEC A-Level Statistics

6.4.1Discrete random variables

Discrete random variables in ZIMSEC A-Level Statistics: what the syllabus expects you to know, the learning objectives and how to practise.

Subtopic21 practice questions1 lesson

Overview

Form 5.

What the syllabus expects you to be able to do.

6.4.1.1Form 5: define a random variable and construct a probability distribution table.
6.4.1.2Form 5: define expectation and calculate the mean, variance and standard deviation.

A sample question on this topic. Answer it, check it, then read the worked answer.

The number of punctures, $X$ , that a kombi on the Mutare road has in a month has the distribution below. Find $\mathrm{E}(X)$ .

x	0	1	2	3
P(X = x)	0.1	0.45	0.3	0.15

Your answer

Unit (optional)

Only if the answer has a unit, e.g. cm or km/h.

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