The table below shows the frequency distribution of daily rainfall, in millimeters, recorded across 50 weather monitoring stations during a storm event.
| Daily Rainfall (mm) | Number of Stations |
|---|---|
| 0 to under 10 | 10 |
| 10 to under 20 | 15 |
| 20 to under 30 | 17 |
| 30 to under 40 | 5 |
| 40 to under 50 | 3 |
What percentage of the stations that recorded at least 10 mm of daily rainfall recorded less than 30 mm of daily rainfall?
- A
- B
- C
- Answer
- E
Answer
To find the desired percentage, first identify the total number of stations that recorded at least 10 mm of rainfall. This includes the intervals 10 to under 20, 20 to under 30, 30 to under 40, and 40 to under 50, giving stations. Next, find how many of these 40 stations recorded less than 30 mm. These fall into the 10 to under 20 and 20 to under 30 intervals, which total stations. Calculating the relative percentage gives .
Step-by-Step Solution
Key Concept
Grouped frequency table interpretation with conditional percentages
Estimated Time:1m 30s