Task
Marmite vs Bieber
You conduct a survey of 100 students.
You discuss their preferences of Marmite and
Bieber.
They were given two options: Love and Hate.
Of those that loved Marmite, 5 also loved Bieber.
60 students hated Marmite.
23 were true Beliebers.
Objectives
Objective
To solve complex expected value
problems using probability.
Keywords
Expected
Value
Two Way
Table
Modelling
Task
Marmite vs Bieber
You conduct a survey of 100 students.
You discuss their preferences of Marmite and
Bieber.
They were given two options: Love and Hate.
Of those that loved Marmite, 5 also loved Bieber.
60 students hated Marmite.
23 were true Beliebers.
Questions
What is the probability
that a student hates
Marmite?
You decide to ask 800
students. How many
do you expect to be
Marmite loving
Belibers?
What percentage of
students hate Bieber?
Create your own
question that matches
a missing answer.
If you ask 20 students
how many do you
expect to love
marmite?
I attend a Bieber
concert and offer
people Marmite
sandwiches. How
many of the 460
Beliebers I ask do I
expect to love my
sandwiches?
If you ask 20 students
how many do you
expect to hate
Marmite?
Create your own
question that matches
a missing answer.
A survey 200 of
Marmite haters is
expected to include
how many Belibers?
What percentage of
Beliebers hate
Marmite?
If I wanted to increase If you ask 231 students
the reliability of my
that hate Justin Beiber
probabilities how
how many do you
many students should
expect to love
I ask?
marmite?
Answers
60
78
105
77
100
0.6
50
40
12
8
1000
60
Hint
Total
Total
Exam Q
Star Q
Capture, Recapture
Georgia wants to estimate the number of frogs in a pond.
One morning she catches 60 frogs and puts a tag on each.
She then releases them back into the pond.
A week later she catches 30 frogs. 12 of these frogs have a
tag.
Estimate the number of frogs in the pond.