The Cafeteria Comeback
The lunch line is a mess: kids wait too long, the food gets cold, and nobody can agree on what to fix. The principal is giving your Student Data Council one shot. Run a real survey, study the numbers with statistics, and walk into the meeting with a data-backed plan to win our cafeteria back.
Your Council Gets the Case
Anybody can complain about lunch. A data scientist measures it. In this WebQuest you become a student data analyst: you will collect a set of numbers, find out what is typical, find out how spread out the data is, and picture the whole story with graphs — then recommend the one change that helps the most students.
The Driving Question
How can one set of numbers be summarized by its center, its spread, and its shape to make a fair decision for a whole school?
The Task
By the end of this WebQuest your council will submit a Cafeteria Data Report. To pass review, your report must:
- Sort four survey questions into statistical vs. not statistical.
- Find the mean, median, and mode of the wait-time data set.
- Measure the spread with the range and the MAD (mean absolute deviation).
- Read a box plot and a histogram and describe the shape of the data.
- Recommend one change and back it with two numbers from your analysis.
- Pass the Check Your Understanding self-check at the bottom.
Your data set (wait time in minutes for 12 students): 4, 5, 5, 6, 6, 6, 7, 7, 8, 9, 11, 14. Keep it handy — you will use it in almost every step.
The Process
Work the steps in order. Each step fills one section of your Cafeteria Data Report.
Step 1 — Decide what is worth measuring
Your council drafted four questions. Tap a chip to label each one. A question is statistical only if you expect the answers to vary from student to student.
Step 2 — Find the center (mean, median, mode)
The center tells the principal what a typical wait looks like. Use your 12-value data set.
add all ÷ how many
The balance point — the "fair share" if everyone waited equally.
middle of the sorted list
With 12 values, average the 6th and 7th numbers.
value that appears most
The most common single wait time.
Worked example — the mean:
Sum = 4+5+5+6+6+6+7+7+8+9+11+14 = 88. Mean = 88 ÷ 12 = 7.33 min (about 7⅓).
Step 3 — Measure the spread (range and MAD)
Two cafeterias can have the same mean but feel totally different — one steady, one wild. Spread captures that. The range is max − min. The MAD (mean absolute deviation) is the average distance of each value from the mean.
How to find the MAD (3 moves):
1) Distance of each value from the mean (7.33).
2) Add up all 12 distances.
3) Divide that total by 12. A
larger MAD means a more inconsistent lunch line.
Step 4 — Picture the data (box plot & histogram)
A graph reveals the shape at a glance. Study the box plot and histogram below — they show the same 12 wait times two ways.
Both graphs show most students bunched around 6–8 minutes, with a thin tail stretching right toward 11 and 14. That makes this distribution skewed right.
Step 5 — Make the call
Write one clear recommendation and support it with two numbers from your analysis (for example: "median wait 6.5 min" and "MAD shows lines vary"). Decide whether a single average is enough, or whether the principal needs the spread and shape too.
Resources
Use these Neft Teacher tools as you work. They open in the same window — use your back button to return.
Key vocabulary · Vocabulario clave
- Statistical question / Pregunta estadística — a question whose answers are expected to vary.
- Mean · Median · Mode / Media · Mediana · Moda — three measures of the center.
- MAD / Desviación media absoluta — the average distance of values from the mean (a measure of spread).
- Distribution / Distribución — the overall shape: symmetric, skewed, clusters, gaps, peaks.
Evaluation
Your Cafeteria Data Report will be scored on this rubric.
| Criteria | 4 · Lead Analyst | 3 · Analyst | 2 · Apprentice | 1 · Getting started |
|---|---|---|---|---|
| Statistical questions | All 4 questions sorted correctly with a reason. | 3 of 4 sorted correctly. | 2 of 4 sorted correctly. | 0–1 sorted correctly. |
| Center | Mean, median, and mode all correct. | Two of three correct. | One correct. | None correct. |
| Spread (range & MAD) | Range and MAD both correct and labeled. | One of two correct. | Attempts MAD with errors. | No spread shown. |
| Graphs & shape | Reads box plot & histogram; names the shape. | Reads one graph; shape unclear. | Partial graph reading. | No graph interpretation. |
| Recommendation | Clear call backed by two numbers. | Call with one number. | Call with no data. | No recommendation. |
Teacher Notes & Answer Key (not printed)
Cafeteria Comeback · Data Report — pairs with the Evaluation rubric above.
Sample Answers — Cafeteria Data Report
- Statistical vs not: "How long did each 6th grader wait?" is statistical (answers vary); "What time is lunch?" is not (one answer).
- Data set 4,5,5,6,6,6,7,7,8,9,11,14 (12 values): Mean = 88 ÷ 12 = 7.33 min; Median = average of 6th & 7th = (6+7)/2 = 6.5; Mode = 6.
- Spread: Range = 14 − 4 = 10; compute MAD as the mean distance of each value from 7.33.
- Shape: mean (7.33) > median (6.5) → a large value (14) pulls the mean up; distribution is skewed right.
Facilitation
- "Would 30 students give different answers?" → yes means statistical.
- Order the data before finding the median; the mode can be read from the histogram's tallest bar.
Standard
CCSS 6.SP.A.1–B.5.
Check Your Understanding
Answer all six using the data set 4, 5, 5, 6, 6, 6, 7, 7, 8, 9, 11, 14. Click Check My Answers when you are done.
Conclusion
You did what real data analysts do every day: you turned a noisy complaint into evidence. You measured the center, the spread, and the shape — and you saw why a single average like the mean (7.33) can hide the real story when one 14-minute wait stretches the data. Walk into that principal's meeting knowing your recommendation stands on numbers, not opinions.
Take it further · Level 2
Suppose a new express line removes the 14- and 11-minute waits. Recompute the mean and median. Did your recommendation get stronger?
Reflect · Reflexiona
Should the principal trust the mean or the median for this data, and why? Explain in 2–3 sentences. ¿Debería confiar en la media o en la mediana, y por qué?
Real careers · Carreras reales
Sports analysts, school nurses, and city planners all summarize messy data with center, spread, and shape — exactly the skills you just used.