Statistics
istical Distribution
Twitter: @Owen134866
www.mathsfreeresourcelibrary.com
, Prior Knowledge Check
1) Three coins are flipped. 2) Two fair dice are rolled.
Calculate the probability Calculate the probability that the
that: sum of the scores on the dice is:
𝟏 𝟏
a) All land on tails 𝟖 a) 5 𝟗
𝟏 𝟏
b) All land on heads 𝟖
b) Even 𝟐
𝟑 𝟏
c) Exactly one lands on tails 𝟖 c) Odd 𝟐
𝟏 𝟏
d) At least 2 land on heads d) Prime 𝟑
𝟐 𝟓
e) A multiple of 3 𝟏𝟐
, achings for
Exercise 6A
, Statistical Distributions
You need to be able to understand and
use probability distributions This chapter focuses on Discrete Random
Variables
A random variable is a variable whose
value depends on the outcome of a These are values which can only take certain
random event numerical values, each of which can be
assigned a probability
For example, when we roll 5 dice, the
number of sixes rolled would be a
random variable
For example, the number of times a 1 is rolled
The range of values the random variable when rolling a dice 10 times
can take is called a sample space, and is
often drawn as a table
It can only take certain numerical values
A discrete variable can only take certain Each can be assigned a probability
countable numerical values
For example, the number of people has
to be a whole number
6A
istical Distribution
Twitter: @Owen134866
www.mathsfreeresourcelibrary.com
, Prior Knowledge Check
1) Three coins are flipped. 2) Two fair dice are rolled.
Calculate the probability Calculate the probability that the
that: sum of the scores on the dice is:
𝟏 𝟏
a) All land on tails 𝟖 a) 5 𝟗
𝟏 𝟏
b) All land on heads 𝟖
b) Even 𝟐
𝟑 𝟏
c) Exactly one lands on tails 𝟖 c) Odd 𝟐
𝟏 𝟏
d) At least 2 land on heads d) Prime 𝟑
𝟐 𝟓
e) A multiple of 3 𝟏𝟐
, achings for
Exercise 6A
, Statistical Distributions
You need to be able to understand and
use probability distributions This chapter focuses on Discrete Random
Variables
A random variable is a variable whose
value depends on the outcome of a These are values which can only take certain
random event numerical values, each of which can be
assigned a probability
For example, when we roll 5 dice, the
number of sixes rolled would be a
random variable
For example, the number of times a 1 is rolled
The range of values the random variable when rolling a dice 10 times
can take is called a sample space, and is
often drawn as a table
It can only take certain numerical values
A discrete variable can only take certain Each can be assigned a probability
countable numerical values
For example, the number of people has
to be a whole number
6A
