Handling Data 4
2 marks · EasyHere is a grouped frequency table showing the ages of attendees at a club:
| Age (years) | Frequency |
|---|---|
| 10–12 | 8 |
| 13–15 | 12 |
| 16–18 | 10 |
Estimate the mean age of the attendees at the club. Give your answer to one decimal place.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
13.8 (±0.1)
Also accept: 13.7; 13.75
Common mistakes: Not using midpoints
Show mark scheme and worked solution
Marking points
M1 · 1 mark · Finds midpoints and multiplies by frequencies: 11 × 8, 14 × 12, 17 × 10
A1 · 1 mark · Adds results, divides by total frequency (30), gives answer to 1 decimal place.
Worked solution
Midpoints: 11, 14, 17
Total frequency = 8 + 12 + 10 = 30