Beth is interested in which students from her school catch public transport.
Determine whether the following sampling methods are likely to be biased or not:
Selecting every 10th person on the bus she catches.
Selecting every 10th person on the student list.
Selecting the first 50 students that arrive in the morning.
Selecting by having a computer randomly choose student numbers.
Georgia wants to know how the people in Australia are going to vote in an upcoming referendum. She selects 50 random people from her suburb to interview.
Determine whether the following are the reasons why this sampling might give poor results:
The sample doesn't include anyone from New Zealand.
Random sampling always leads to a very bias sample.
The people of this suburb are not a good representation of Australia.
The sample size is too small for such a big population.
Justin wants to know how the students at his school might vote for the next school captain. He leaves three flyers in each class to be completed by whichever students want to complete them.
Explain why this method of sampling might give poor results.
Sean wants to know what year 12 students think of their English class, so he polls 70 random year 12's. State whether the sample chosen is likely to be biased or fair.
Explain why the following samples are biased:
Hannah is surveying customers at a shopping precinct. She wants to know which stores customers shop at the most. She walks around an entertainment store and chooses 30 customers from the store for the survey.
A TV station wants to know what the most popular type of music is, so they ask listeners to contact them and vote for their favourite type of music.
A school principal wants to estimate the number of students who ride a bicycle to school. State whether the following samples will avoid bias:
All students who are in the school band.
8 students in the hallway.
Ten students from each grade, chosen at random.
130 students during the lunch periods.
The community health nurse wants to survey the students in a school about their eating habits. At lunchtime, she stands by a vending machine and surveys every student who purchases something from the machine.
Explain why this sample is biased.
State whether the following scenarios use biased sampling methods:
A community nurse wants to know the average height of all year 12's that attend the school where she visits, so she measures the height of all the basketball players.
A city councilman asks members of the ice hockey team if they would prefer a new skateboard park or a new ice-skating rink to be built as the new building project.
The lifeguard of a water park wants to determine which water rides are enjoyed the most so he asks every tenth person who leaves the park to list their three favourite rides.
Select the type of sampling error for each of the scenarios from the following three options:
The sample is too small.
The sample is not random.
The sample does not adequately represent the population.
Tina wants to know which new smart phone she should buy and decides to base her decision on other people’s opinions. She decides to interview some people at the retirement home where her grandparents live.
In order to gauge how Australians feel about immigration, a local newspaper sent a reporter to go door-knocking in a local suburb and to ask a series of questions.
For the 2020 US Presidential election, a sample of 10\,000 people in New York were polled to see who they would vote for.
Vincent is conducting research on the average price of 1 \text{ L} of milk in Victoria. He visits two shopping centres, two delis and one convenience store to collect this information.
In 2016, the Australian census was conducted online for the first time and the website crashed. Is this an example of sampling error or measurement error or neither?
An online store sent a survey to all people who had bought the most recent book in the Harry Potter series and asked them “Which do you prefer, the Harry Potter books or the Harry Potter films?”
State whether the following are reasons why there is sampling error in this question:
Those who bought the book are not indicative of the whole population.
The sample is not random.
The sample is too small.
State whether the following are reaons why there is measurement error in this sample:
This question holds an assumption.
This is a leading question.
The scale provided to answer this question is inadequate.