Encouraging recycling in public spaces can be challenging, and simple visual cues may help. An environmental psychologist investigated the effect of placing a footprint sticker leading to a recycling bin to see if this reduced the amount of recyclable waste incorrectly thrown into the general waste bin.
She conducted a field experiment using a small sample of 12 office workers obtained using opportunity sampling. For Week 1, participants recorded the number of times they incorrectly threw a recyclable item into the general waste bin. For Week 2, footprint stickers were placed on the floor leading to the recycling bin, and the same participants recorded their incorrect disposals again. The data is presented below:
| Participant | Number of times recyclable items thrown in general waste bin during one week | |
|---|---|---|
| Without footprint sticker | With footprint sticker | |
| a | 16 | 12 |
| b | 22 | 19 |
| c | 40 | 28 |
| d | 32 | 24 |
| e | 20 | 15 |
| f | 9 | 10 |
| g | 27 | 21 |
| h | 15 | 15 |
| i | 21 | 22 |
| j | 18 | 12 |
| k | 25 | 20 |
| l | 24 | 24 |
The incorrect waste disposal of participant (c) was less during the week with the footprint sticker than in the week without the footprint sticker. Calculate this reduction as a percentage. Show your workings.
