Math 8 · Unit 16: Interpreting and discussing results · Cambridge Lower Secondary Maths Stage 8

Questions

1. 1. Midpoint of the class 10 ≤ t < 20?

   • 30
   • 15
   • 20
   • 10
   Check

2. 2. In a frequency diagram for continuous data, bars …

   • overlap
   • touch
   • have gaps
   • are lines
   Check

3. 3. The frequency diagram shows some times. What is the modal class?

   • 10–20
   • 0–10
   • 20–30
   • 9
   Check

4. 4. The frequency diagram shows some times. What is the total frequency?

   • 30
   • 9
   • 60
   • 19
   Check

5. 5. A frequency polygon joins …

   • the bottoms of the bars
   • the corners of the bars
   • the midpoints of the tops of the bars
   • the class boundaries
   Check

6. 6. Where does a time of exactly 20 s go: 10 ≤ t < 20 or 20 ≤ t < 30?

   • both
   • neither
   • 10 ≤ t < 20
   • 20 ≤ t < 30
   Check

7. 7. Classes 0–10: 4, 10–20: 9, 20–30: 6. Estimate the total using midpoints.

   • 190
   • 305
   • 290
   • 60
   Check

8. 8. Why is the mean from grouped data only an estimate?

   • classes overlap
   • we used a calculator
   • the data is wrong
   • we don't know the exact values in each class
   Check

9. 9. Class width of 30 ≤ h < 45?

   • 30
   • 45
   • 75
   • 15
   Check

10. 10. Two frequency polygons on one grid are used to …

    • list data
    • find the mode only
    • compare two sets of data
    • draw a pie chart
    Check

11. 11. Which data is continuous?

    • times to run 100 m
    • shoe sizes
    • favourite colours
    • number of pets
    Check

12. 12. Midpoint of 1.5 ≤ x < 2.0?

    • 2
    • 1.75
    • 3.5
    • 1.5
    Check

13. 13. Estimated mean = total of (midpoint × frequency) ÷ …

    • the largest midpoint
    • total frequency
    • 100
    • number of classes
    Check

14. 14. Classes 0–10: 2, 10–20: 2. Estimated mean?

    • 10
    • 20
    • 5
    • 15
    Check

15. 15. The frequency diagram shows 19 times. Which class contains the median?

    • 20–30
    • 0–10
    • 10–20
    Check