8.3 Interpreting Fire Department Data, Charts & Tables

8.3 Interpreting Fire Department Data, Charts & Tables

Modern fire service management relies heavily on data collection. Firefighters and officers document response times, incident types, staffing rosters, and equipment usage logs. On the NFSI Mathematical Reasoning section, IO Solutions presents tabular data and charts to evaluate your ability to extract relevant numbers, cross-reference multiple data dimensions, calculate statistical metrics (averages, totals, percentages), and identify operational trends under time pressure.

No calculators are permitted during the NFSI. Success depends on disciplined scratchwork, careful reading of row/column headings, and precise execution of manual arithmetic.

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Section 1: Fire Department Response Time Logs

Response time logs record timestamps for key incident milestones:

• Call Received Time: When the 911 dispatch center receives the emergency call.
• Dispatch Time: When the fire station alert is broadcast to apparatus units.
• En Route Time: When the apparatus leaves the station bay.
• Arrival Time: When the apparatus arrives at the emergency scene location.

$\text{Turnout Time} = \text{En Route Time} - \text{Dispatch Time}$ $\text{Travel Time} = \text{Arrival Time} - \text{En Route Time}$ $\text{Total Response Time} = \text{Arrival Time} - \text{Call Received Time}$

Sample Data Table: Station Response Log

Worked Example 3.1: Average Response Time Calculation

Problem: Based on the Station Response Log above, calculate the average Total Response Time (from Call Received to Arrival) for incidents handled by Station 1.

• Step 1: Identify incidents assigned to Station 1.
• Step 2: Calculate Total Response Time for Incident 101.
• Step 3: Calculate Total Response Time for Incident 103.
• Step 4: Sum the response times and divide by count.
• Result: The average total response time for Station 1 is $6\text{ minutes } 00\text{ seconds}$.

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Section 2: Annual Departmental Call Breakdown & Percentages

Fire departments categorize annual call volume into incident types to justify budget requests and staffing allocations.

$\text{Percentage of Total Volume} = \left( \frac{\text{Category Call Volume}}{\text{Total Call Volume}} \right) \times 100\%$

Sample Data Table: Annual Incident Statistics

Worked Example 3.2: Category Percentage Determination

Problem: What percentage of total Year 1 emergency calls were Emergency Medical Services (EMS) calls?

• Step 1: Extract EMS Year 1 volume and Total Year 1 volume.
• Step 2: Set up the fraction.
• Step 3: Simplify the fraction without a calculator.
• Step 4: Convert fraction to percentage.
• Result: EMS calls accounted for $70%$ of total Year 1 incidents.

Worked Example 3.3: Percentage Increase Between Reporting Years

Problem: What was the percentage increase in Hazardous Materials incidents from Year 1 to Year 2?

$\text{Percentage Change} = \left( \frac{\text{Year 2 Value} - \text{Year 1 Value}}{\text{Year 1 Baseline Value}} \right) \times 100\%$

• Step 1: Extract Year 1 and Year 2 HazMat call numbers.
• Step 2: Calculate absolute increase.
• Step 3: Divide absolute increase by Year 1 baseline.
• Step 4: Convert to percentage.
• Result: Hazardous Materials incidents increased by $30%$ from Year 1 to Year 2.

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Section 3: Shift Rosters & Staffing Tables

Staffing tables monitor firefighter availability, overtime hours, and shift compliance. Questions frequently ask candidates to identify deficit stations or total overtime costs.

Sample Data Table: Daily Shift Staffing Roster

Worked Example 3.4: Staffing Deficit Determination

Problem: If off-duty personnel must be called in on overtime to bring all stations up to minimum staffing levels, how many total overtime personnel must be assigned for this shift?

• Step 1: Calculate deficit for each station (Minimum Staffing - On-Duty Count).
• Step 2: Sum all station deficits.
• Result: A total of 3 overtime personnel are required.

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NFSI Test-Taking Strategies for Data Tables

1. Read Labels First: Always check table titles, column headers, and footnote units before looking at numbers.
2. Isolate the Target Row/Column: Place a finger or straight edge on your scratch paper under the target row to prevent reading values from adjacent lines.
3. Verify Totals: Quickly add up row or column items to ensure the table total matches your mental calculation baseline.