Case 01: The Screen-Time Case
Ten answers, one chart, and one number that changes the whole story.
Ten people answered a survey about sleep and screen time. The average says one thing. The middle person says another. Your job is to find out which one is telling the truth.
The data below is made up for the video. Yours will be real.
Your mission
- Ask at least 10 real people. Ask permission first, and a no is a no.
- Collect no names, emails or school names. Less data means less to leak.
- Find the average and the median of screen time. Work out why they differ.
- Find your weirdest number, the outlier. Don’t delete it silently. Say what you did and why.
- Write one honest sentence: what do your answers show, and what do they not prove?
The evidence
Hours of screen time yesterday, one bar per person:
| # | Age group | Sleep (h) | Screen (h) | Phone in bed |
|---|---|---|---|---|
| 1 | 13–15 | 7 | 4 | Yes |
| 2 | 16–18 | 6 | 6 | Yes |
| 3 | 13–15 | 8.5 | 2.5 | No |
| 4 | 16–18 | 6.5 | 5 | Yes |
| 5 | 19+ | 7.5 | 3.5 | No |
| 6 | 16–18 | 6 | 5.5 | Yes |
| 7 | 19+ | 8 | 3 | No |
| 8 | 13–15 | 7.5 | 4 | No |
| 9 | 16–18 | 7 | 5 | Yes |
| 10 | 13–15 | 7 | 14 | Yes |
The twist. One 14-hour answer drags the average up. A phone left running, or a typo? Ask before you assume.
Sleep against screen time: the link looks weak with the outlier (-0.37) and strong without it (-0.96). One row changed the story, which is why you always say what you did with it.
Get the files
The sheet has four tabs: Data, Your Turn, Answer Key and Read Me. Try the Answer Key yourself before you peek.
Challenge
Run the survey on 10 real people. Find your outlier. Send us your one honest sentence, with no names and no faces. The best ones may be featured, only with a parent’s written consent.
Decoder words in this case
Average, median, outlier, correlation, dataset. See the Decoder.
Case closed
Parent note: this case collects no personal data, and the survey should stay anonymous.
Last updated: [date]. Next case: Case 02: Charts That Lie (Opens soon)