CompTIA Data+ (DA0-002)Data AnalysisMedium

A data analyst is presented with a dataset of customer transaction values. The values are: $25, $30, $35, $40, $45, $50, $55, $60, $65, $70. What is the median of this dataset?

  1. A$50.00
  2. B$47.50
  3. C$40.00
  4. D$45.00
Show answer & explanation

Correct answer: B. $47.50

The dataset has 10 values, an even number. To find the median, take the average of the two middle values. The ordered dataset is $25, $30, $35, $40, $45, $50, $55, $60, $65, $70. The two middle values are $45 (5th position) and $50 (6th position). The median is ($45 + $50) / 2 = $47.50.

Why the other options are wrong

  • A. This is the 6th value, not the average of the middle two values.
  • C. This is the 4th value, not one of the middle two values.
  • D. This would be the median if there were an odd number of data points and $45 was the single middle value.

Median

The middle value in a dataset that is ordered from least to greatest.

  • Robust to outliers and skewed distributions.
  • For an odd number of values, it's the single middle value.
  • For an even number of values, it's the average of the two middle values.

Memory trick: MEDIAN: The middle path, ordered first!

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