To find out how many people were included in the sample, you can count all the individual responses:
- 17: 2 responses
- 6: 2 responses
- 18: 2 responses
- 7: 1 response
Now, add them up:
2 (17s) + 2 (6s) + 2 (18s) + 1 (7) = 2 + 2 + 2 + 1 = 7 responses.
So the number of people included in the sample is 7.