8.01 Random sampling
Interactive practice questions
Beth is interested in which students from her school catch public transport. Select whether the following sampling methods are likely to be biased or not.
Selecting every $10$10th person on the bus she catches.
Biased
Not biased
Selecting every $10$10th person on the student list.
Biased
Not biased
Selecting the first $50$50 students that arrive in the morning.
Biased
Not biased
Selecting by having a computer randomly choose student numbers.
Biased
Not biased
Georgia wants to know how the people in Australia are going to vote in an upcoming referendum. She selects $50$50 random people from her city to interview.
Why might this sampling give poor results?
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 complete by whatever students want to complete them.
Why might this sampling give poor results?
Four lucky people from a group of $215$215 each stand to win an iPad. Every contestant is given a different number between $1$1 and $215$215, and the winners are selected by generating a random number uniformly between $0$0 and $1$1.
To ensure there is an equal chance of each contestant winning, the number is multiplied by $215$215 and then rounded up. In this case the numbers generated were:
| $0.152$0.152 | $0.534$0.534 | $0.352$0.352 | $0.795$0.795 |