Math 9 · Unit 6: Statistical investigations · Cambridge Lower Secondary Maths Stage 9

Questions

1. 1. You investigate how long learners spend playing computer games. Which is a factor that could affect this, apart from age?

   • the number of questions asked
   • the colour of the school
   • the day of the survey's title
   • how much free time they have
   Check

2. 2. In the computer games investigation, which is a question you could ask?

   • What is your name?
   • Is gaming good?
   • How many hours a week do you spend playing computer games?
   • Do you like school?
   Check

3. 3. Which prediction could you test in the computer games investigation?

   • Computers are expensive.
   • Learners go to school.
   • Games are fun.
   • Older learners spend more time playing games than younger learners.
   Check

4. 4. Which is the better way to take a sample of learners?

   • choose learners at random from every year group
   • ask only learners in the computer club
   • ask only your friends
   • ask the first five learners you meet
   Check

5. 5. Which factor could affect the number of passengers in a car?

   • the time of day
   • the weather forecast's presenter
   • the length of the road
   • the colour of the car
   Check

6. 6. Which is a prediction you could test about passengers in cars on a busy road?

   • Cars have more passengers at weekends than on weekdays.
   • Passengers like cars.
   • Roads are long.
   • Cars are red.
   Check

7. 7. In the passengers investigation, which sample would be biased?

   • counting cars at different times on different days
   • counting cars only between 8 and 9 a.m. on a Monday
   • counting cars on weekdays and weekends
   • counting every 10th car for a week
   Check

8. 8. Which is a random way to choose a sample of cars on a road?

   • Record only cars that stop near you.
   • Record every 10th car that passes.
   • Choose only red cars.
   • Choose cars you like.
   Check

9. 9. Which is a good question to ask in an investigation of writing speed?

   • Do you like typing?
   • Do people write faster on paper or with a keyboard?
   • Is writing fun?
   • What is your favourite pen?
   Check

10. 10. Which prediction could you test about writing speed?

    • Pens are blue.
    • Keyboards have keys.
    • Writing is important.
    • People write faster with a keyboard than on paper.
    Check

11. 11. You are going to investigate the speed with which people can write either on paper or using a keyboard. Which is the best way to choose a sample?

    • ask only your friends
    • choose learners at random from each year group
    • ask only the fastest typists in the school
    • ask only learners from one class
    Check

12. 12. Why is it a good idea to carry out a small trial before an investigation?

    • to find problems and improve the plan
    • to decide the answer in advance
    • so you don't need a sample
    • to make the results bigger
    Check