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Kazakhstan FAIO 2025 · Statement

Problem 1: Stats 101

Formatted by IOAI Training from the original (BeksultanSagyndyk/faio-tasks, licence Apache-2.0). The original is authoritative.

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Problem 1

The correct answer to this problem is worth 10 points.

Problem Statement

There are 10 students in a class. Each of them reported how many pets they have. The numbers were as follows:

2,0,1,3,2,1,0,4,1,12, 0, 1, 3, 2, 1, 0, 4, 1, 1
  1. Find the mean number of pets.
  2. Determine the mode.
  3. Find the median.

Theory

Mean
The arithmetic mean is the result of dividing the sum of all numbers in a set by their total count.
Example in data analysis: The average customer purchase amount.
Example in ML: Mean Squared Error (MSE).

Mode
Formal definition: value that appears most often in a set of data values.
Example in data analysis: The most popular item in an online store.
Example in ML: Choosing the final class by model voting.

Median
Simple explanation: It's the middle value in an ordered list of numbers.
Formal definition: The median divides a dataset in half — 50% of the values are smaller, and 50% are larger.
Example in data analysis: Median salary.
Example in ML: Median Absolute Error.


Answer Format

Output three numbers on a single line, separated by a space: first the mean, then the mode, and then the median.

Example for answer output

99 3.14 2.72