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

Questions

1. 1. At a concert, 56% of the audience are female and 44% are male. How many females should be in a representative sample of 60?

   • 34 (to the nearest whole person)
   • 56
   • 30
   • 26
   Check

2. 2. At a concert, 44% of the audience are male. How many males should be in a representative sample of 60?

   • 16
   • 30
   • 26 (to the nearest whole person)
   • 44
   Check

3. 3. A teacher chooses five learners for a survey. Why could this sample be biased?

   • Five is too many.
   • Teachers know the answers.
   • The teacher might choose learners who are not typical of the class.
   • The sample is random.
   Check

4. 4. You want a representative group of five learners from a class. Which is a better way to choose them?

   • Choose the five learners who sit at the front.
   • Give every learner a number and pick five numbers at random.
   • Ask the teacher to choose the five best learners.
   • Ask for five volunteers.
   Check

5. 5. A radio programme asks listeners to phone in with their opinion of a company. 72% are negative. Why could this be biased?

   • People with strong, often negative, opinions are more likely to phone.
   • The company chose the callers.
   • 72% is too high.
   • Radio listeners can't count.
   Check

6. 6. A radio programme asks listeners to phone in with their opinion of an insurance company. Which is a better way to get a sample of opinions?

   • Choose customers at random from the insurance company's list and ask them.
   • Ask only people who have complained.
   • Ask only the listeners who phone in.
   • Ask the radio presenter's friends.
   Check

7. 7. Which is a disadvantage of asking about a new shopping centre on social media?

   • It is too expensive.
   • It is very slow.
   • Nobody can answer online.
   • Only people who use social media will answer.
   Check

8. 8. Which is a disadvantage of testing opinions about a new shopping centre by sending letters to people?

   • Everybody has to reply.
   • Many people may not reply, so the sample could be small and biased.
   • Only people in the street receive them.
   • Letters cannot be read.
   Check

9. 9. Which is a disadvantage of testing opinions about a new shopping centre by asking people in the street?

   • Everyone in the town is asked.
   • It takes no time at all.
   • Only people who happen to be in that street at that time are asked.
   • People cannot answer face to face.
   Check

10. 10. This table shows the ages of people who live in a village. You want a representative sample of 50 people. How many people from each age group should be in the sample (under 18, 18 to 55, over 55)?

    • 7, 31 and 12
    • 10, 30 and 10
    • 7, 30 and 13
    • 5, 33 and 12
    Check

11. 11. Look at this advert. Does the advert prove that anti-wrinkle cream works?

    • Yes
    • No
    Check

12. 12. An advert says 81% of women found a cream made them look younger, based on 48 women for a month. Which question checks if this is reliable?

    • What colour is the cream?
    • Is 81 more than 48?
    • How much does the cream cost?
    • Who chose the women, and did they know what was being tested?
    Check

13. 13. A pie chart shows 'Yes 81%' for the cream. What important information is missing?

    • the colour of the pie chart
    • the date of the advert
    • the price of the cream
    • how many people were asked and what the other 19% said
    Check

14. 14. Three survey questions are: 'Do you eat five fruit or vegetable portions a day?', 'Do you eat too much meat?' and 'Do you agree that people are overweight because they are greedy and eat too much?' Why could each give biased results?

    • Each one has no possible answer.
    • Each one is too long.
    • Each one suggests the answer the person is expected to give.
    • Each one is about food.
    Check

15. 15. Which is a better version of 'Do you agree that people are overweight because they are greedy?'

    • Are greedy people overweight?
    • Do you agree?
    • What do you think are the main reasons people become overweight?
    • Why are people greedy?
    Check

16. 16. 40% of a group of teachers are men and 60% are women. You have data from 28 men. How many women should you ask for a representative sample?

    • 42
    • 60
    • 70
    • 28
    Check

17. 17. You want to do a survey of the parents of 50 learners in your school. How will you choose a representative sample?

    • Ask the parents of the 50 learners in one class.
    • Ask the first 50 parents who arrive at the school gate.
    • Ask the parents of 50 learners who volunteer.
    • Choose the 50 learners at random from a list of all learners, then ask their parents.
    Check