topic badge

11.03 Variance and standard deviation

Interactive practice questions

Consider the table.

$x$x $0$0 $1$1 $2$2 $3$3 $4$4
$P$P$($($X=x$X=x$)$) $0.12$0.12 $0.15$0.15 $0.22$0.22 $0.23$0.23 $0.28$0.28
a

Does the table represent a discrete probability distribution?

Yes

A

No

B
b

Calculate $E\left(X\right)$E(X).

c

Calculate the variance of $X$X.

d

Hence calculate the standard deviation.

Give your answer to two decimal places.

Easy
5min

A uniform discrete random variable $X$X has values $x=1,2,3,4,5$x=1,2,3,4,5.

Medium
3min

Consider the graph drawn below of a discrete probability distribution.

Medium
4min

Consider the probability distribution shown.

Medium
4min
Sign up to access Practice Questions
Get full access to our content with a Mathspace account

Outcomes

MA11-7

uses concepts and techniques from probability to present and interpret data and solve problems in a variety of contexts, including the use of probability distributions

What is Mathspace

About Mathspace