topic badge

7.03 Centre and spread of discrete random variables

Interactive practice questions

Consider the table.

$x$x $0$0 $1$1 $2$2 $3$3 $4$4
$P$P$($($X=x$X=x$)$) $0.1$0.1 $0.45$0.45 $0.15$0.15 $0.05$0.05 $0.25$0.25
a

Does the table represent a discrete probability distribution?

Yes

A

No

B
b

What is the most likely outcome for the random variable $X$X?

c

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

Easy
2min

Consider the probability distribution table shown for the random variable $X$X.

Easy
1min

Consider the probability distribution shown.

Easy
1min

Consider the probability distribution table shown for the random variable $X$X.

Easy
1min
Sign up to access Practice Questions
Get full access to our content with a Mathspace account

Outcomes

3.3.2

use relative frequencies obtained from data to obtain point estimates of probabilities associated with a discrete random variable

3.3.3

identify uniform discrete random variables and use them to model random phenomena with equally likely outcomes

3.3.5

identify the mean or expected value of a discrete random variable as a measurement of centre, and evaluate it in simple cases

3.3.6

identify the variance and standard deviation of a discrete random variable as a measures of spread, and evaluate them using technolgy

3.3.7

examine the effects of linear changes of scale and origin on the mean and the standard deviation

3.3.8

use discrete random variables and associated probabilities to solve practical problems

What is Mathspace

About Mathspace