1. **State the problem:** We have a dot plot showing shower times (in minutes) for 20 students, with a total shower time of 180 minutes. 2. **Given data:** - Water flow rate = 3.5 gallons per minute - Total shower time = 180 minutes - Number of students = 20 3. **Goal:** Find how many students used less than 30 gallons of water. 4. **Formula:** Water used by a student = Shower time (minutes) \times Flow rate (gallons/minute) 5. **Calculate the maximum shower time for less than 30 gallons:** $$\text{Water used} < 30$$ $$3.5 \times \text{time} < 30$$ Divide both sides by 3.5: $$\cancel{3.5} \times \text{time} < \frac{30}{\cancel{3.5}}$$ $$\text{time} < \frac{30}{3.5} = 8.5714 \text{ minutes}$$ 6. **Interpretation:** Students who showered less than approximately 8.57 minutes used less than 30 gallons. 7. **Count students with shower times less than 8.57 minutes from the dot plot:** - Shower times and counts: - 5 min: 1 student - 6 min: 2 students - 7 min: 3 students - 8 min: 4 students - 9 min: 3 students - 10 min: 4 students - 11 min: 2 students - 12 min: 1 student - 13 min: 1 student - 14 min: 1 student - 15 min: 1 student Only students with times 5, 6, 7, and 8 minutes qualify. Number of students = 1 + 2 + 3 + 4 = 10 **Final answer:** **10 students used less than 30 gallons of water showering yesterday.**