Mean and Variance

This image is an Excel spreadsheet tutorial that demonstrates how to calculate the mean and variance of a dataset. Here’s a breakdown of each section:

Title and Purpose

• Title: Mean and Variance

• Source: softexperia.com | Excel Tips

• Purpose: To teach how to calculate mean and variance using Excel formulas, with data entry highlighted in yellow for clarity.

Table Columns Explained

1. Ονοματεπώνυμο / Name:
   Names of individuals (e.g., Papadopoulos Trifon, Adamopoulou Sofia)

2. Data Value (X):
   Values assigned to each person (e.g., 12, 15, 18, etc.)

   • This column has a yellow background, indicating it’s for user data entry.

3. X – μ (X minus mean):
   The difference between each data value and the mean (μ = 19.20).

4. (X – μ)²:
   The square of the difference in column 3, used to calculate variance.

Summary Row

• N: Number of data points = 6

• Mean (μ): Calculated as 19.20

• Variance: Calculated as 76.8

Formulas Used

• Mean (B16):
  =SUM(B6:B11)/B13
  Adds all values in column B (rows 6–11) and divides by N (in B13).

• Variance (D16):
  =SUM(D6:D11)/B13
  Adds all squared differences in column D (rows 6–11) and divides by N.

Interpretation

This example guides users to:

• Enter data (yellow cells).

• Use Excel to calculate mean and variance.

• Understand the steps of subtracting the mean and squaring the result to compute variance.