The table lists performance and cost metrics for 10 municipal water treatment facilities during the 2025 fiscal year:
| Facility ID | Region | Daily Capacity (MGD) | Average Turbidity (NTU) | Operating Cost ($/thousand gallons) |
|---|---|---|---|---|
| W-01 | North | 24.0 | 0.12 | 1.42 |
| W-02 | South | 18.0 | 0.25 | 1.85 |
| W-03 | North | 32.0 | 0.08 | 1.28 |
| W-04 | Central | 12.0 | 0.19 | 1.65 |
| W-05 | South | 28.0 | 0.15 | 1.56 |
| W-06 | Central | 40.0 | 0.10 | 1.18 |
| W-07 | North | 15.0 | 0.22 | 1.70 |
| W-08 | South | 22.0 | 0.14 | 1.50 |
| W-09 | Central | 35.0 | 0.11 | 1.34 |
| W-10 | North | 10.0 | 0.28 | 1.92 |
Based on the data provided, what is the median operating cost, in dollars per thousand gallons, for the facilities that have a daily capacity greater than 20.0 MGD?
Cevap: 1.38 $/thousand gallons
Cevap
The median operating cost for facilities with a daily capacity greater than 20.0 MGD is $1.38 per thousand gallons.
Filtering the table for facilities with Daily Capacity > 20.0 MGD yields 6 facilities (W-01, W-03, W-05, W-06, W-08, W-09). Sorting their operating costs in ascending order produces: 1.28, 1.42, 1.56. Because the count of elements is even (6), the median is the average of the 3rd element ( 1.42), which equals $1.38.
Adım Adım Çözüm
Anahtar Kavram
Calculating the median of a filtered even-count subset from tabular data.
Alternatif Yöntem
As a verification step, sum all operating costs in the filtered set: . The mean is . In this symmetric subset, the mean and median coincide at .
Tahmini Süre:2m 0s