Student Hydration and School Fountains: A Random-Sample Survey

Driving question: What keeps students at our school from drinking the school's tap water, and which three changes would most increase how often they do?

Your client is the school wellness committee. The committee wants a short written proposal and a five-minute presentation that it can use to decide how to spend a small grant.

Health background. Water is the recommended everyday drink for teenagers because it hydrates without adding sugar or calories. Sugary drinks such as soda, sweet tea, and many sports and energy drinks are a leading source of added sugar in teen diets. Sipping them often through the day also feeds the mouth bacteria that cause tooth decay. Even mild dehydration can leave people tired, headachy, and less able to focus, and students who play sports or take PE lose extra water through sweat. Research on schools finds that students drink more water when it is easy to reach, cold, and good-tasting, and when they trust that it is safe.

Water inside the building. Public water systems treat and test the water they deliver to the school. Inside the building, though, water can pick up warmth, off-tastes, or metals such as lead from old pipes and fixtures. This is most likely after the water sits unused over a weekend or a break. For that reason, many schools flush their lines, test their fountains, and replace old fixtures, and posting the test results can affect whether students decide to drink.

A pilot survey to learn from. In our scenario, a statistics class at the fictional Rushbrook High School, which has 1,400 students, surveyed a random sample of 120 students. They chose the sample by drawing advisory classes at random. Of the 120 students, 54 answered yes to this question: "Yesterday, at school, did you drink water from a school fountain or bottle filler?" The 66 students who answered no could give more than one reason.

Constraints your team must meet:

• Sample: survey a random sample of at least 80 students, or the number your teacher sets. Choose it by drawing advisory classes at random or from a random list, never by asking whoever is nearby.
• Survey: it must be anonymous and voluntary, approved by your teacher and principal, and no longer than 8 questions. It must include the Rushbrook question word for word so your result can be compared with theirs. Do not ask about medical conditions or anything that could identify a student.
• Audit: record every drinking fountain and bottle filler in the building in the audit table below.
• Budget: in our scenario, the committee has a fictional grant of $5,000. Your three recommendations must fit within it, using these fictional prices.

• Balance: include one change aimed at access (where water is and whether it works), one aimed at trust (whether students believe it is safe), and one aimed at habits (whether students think to drink).

Fountain audit table (one row per outlet):

Final deliverables:

• A written proposal of two to three pages that includes your sampling method, your estimate with its margin of error, a chart of the reasons students gave, a summary of the audit, three recommendations with costs and the evidence behind each, and a paragraph on the limits of your study.
• A five-minute presentation to the wellness committee, or to a panel of classmates and staff playing the committee.

1. Session 1: Health background, survey draft, and sampling plan. Read the Project Brief and discuss which Rushbrook reasons you expect to see at your school. Draft a survey of no more than 8 questions that includes the required yes or no question. Write a sampling plan that names how many advisory classes you will draw, how you will draw them at random, and about how many students that gives you. Output: the draft survey and sampling plan, approved by your teacher.

2. Session 2: Fountain audit and pilot test. In pairs, visit every outlet on the floor plan and complete one row of the audit table for each. Run the water for 5 seconds before taking its temperature, and time how long it takes to fill the 500 mL bottle. Then try your survey on five classmates and fix any question they found unclear. Output: the completed audit table and the final survey with a list of changes. Between Sessions 2 and 3, give the survey in the advisory classes you drew, following your teacher's schedule.

3. Session 3: Data entry and first look. Enter every response, remove blank or duplicate forms, and find your sample proportion for the required question. Make a bar chart of the reasons students gave, and put your proportion next to Rushbrook's 54 out of 120. Output: a cleaned data file, your sample proportion, and the reasons chart.

4. Session 4: Margin of error and health analysis. Practice first with the Rushbrook result. Use a random number generator to simulate at least 200 samples of 120 students, where each simulated student answers yes with probability 54/120. Find the middle 95 percent of the simulated proportions and the margin of error it gives. Repeat the process with your own sample size and sample proportion. Then write one paragraph that links your two most common reasons to student hydration and health. Output: your estimate stated as a proportion plus or minus a margin of error, and the health paragraph.

5. Session 5: Proposal and presentation. Choose three changes that meet the balance rule and fit within the $5,000 budget, and connect each one to a specific finding from your survey or audit. Finish the written proposal, including its limits paragraph, and present it to the committee or panel. Output: the final proposal and the five-minute presentation.