Step 1: Find the mean (average) of the data set. Add all the numbers together: 1 + 2 + 3 + 4 + 5 = 15. Then divide by the number of values (5): 15 / 5 = 3.
Step 2: Subtract the mean from each number in the data set to find the differences: (1-3), (2-3), (3-3), (4-3), (5-3) which gives us: -2, -1, 0, 1, 2.
Step 3: Square each of the differences: (-2)² = 4, (-1)² = 1, (0)² = 0, (1)² = 1, (2)² = 4. So we have: 4, 1, 0, 1, 4.
Step 4: Add all the squared differences together: 4 + 1 + 0 + 1 + 4 = 10.
Step 5: Divide the total by the number of values (5) to find the variance: 10 / 5 = 2.
