GMAT Focus EditionQuantitative ReasoningMedium
A data analyst is examining a dataset of customer purchase amounts. The purchases range from $10 to $100. If the analyst wants to categorize these purchases into 6 equally sized bins (intervals), what would be the width of each bin?
- A$15
- B$10
- C$20
- D$25
Show answer & explanationAnswer & explanation
Correct answer: A. $15
The range of the data is the maximum value minus the minimum value: $100 - $10 = $90. To divide this range into 6 equally sized bins, divide the total range by the number of bins: $90 / 6 = $15. The width of each bin will be $15.
Why the other options are wrong
- B. This would be the width if there were 9 bins (90/9=10).
- C. This would be the width if there were 4.5 bins, or if the range was 120 (120/6=20).
- D. This would be the width if there were 3.6 bins, or if the range was 150 (150/6=25).
Bin Width (Data Grouping)
Bin width, also known as interval width, is the size of each category or interval when grouping continuous data into bins for analysis or visualization (e.g., histograms).
- Calculated as (Max Value - Min Value) / Number of Bins.
- All bins typically have the same width.
- Choosing appropriate bin width is important for data representation.
Memory trick: Range Divided by Bins, Width Defined.