Calculate mean, median, mode and range

key notes :

Mean:

• Definition: The mean (average) is found by adding up all the numbers in a data set and dividing by the number of items.
• Formula: Mean = (Sum of all numbers) / (Number of items)
• Example: Calculate the mean of the numbers 12, 15, 18, 20, and 25:
  • Mean = (12 + 15 + 18 + 20 + 25) / 5
  • Mean = 90 / 5
  • Mean = 18

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Median:

• Definition: The median is the middle value in a sorted list of numbers. If there’s an even number of values, it’s the average of the two middle numbers.
• Steps:
  1. Arrange the numbers in ascending order.
  2. If the number of items (n) is odd, the median is the (n+1)/2-th item.
  3. If the number of items (n) is even, the median is the average of the n/2-th and (n/2 + 1)-th items.
• Example: Find the median of 12, 15, 18, 20, and 25:
  • Arranged in order: 12, 15, 18, 20, 25
  • Median = 18 (middle value)

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Mode:

• Definition: The mode is the number that appears most frequently in a data set.
• Example: In the set 12, 15, 18, 20, 20, 25:
  • Mode = 20 (appears most frequently)

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Range:

Range = 13

Definition: The range is the difference between the largest and smallest values in a data set.

Formula: Range = Largest value – Smallest value

Example: For the numbers 12, 15, 18, 20, and 25:

Range = 25 – 12

Learn with an example

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