The given mathematical expression is:

$\sum_{i=1}^{3} (x_i - 1)^2$

This means we need to evaluate the sum of squared differences for $i = 1$ to $i = 3$:

$(x_1 - 1)^2 + (x_2 - 1)^2 + (x_3 - 1)^2$

This is a common expression used in statistical analysis, particularly in variance calculations.

Do you have specific values for $x_1, x_2, x_3$ that you want to substitute? Or would you like a general explanation of its significance?

Related Questions:

1. What does summation notation represent in mathematics?
2. How is this expression related to variance in statistics?
3. How can we expand and simplify this sum algebraically?
4. What happens if all $x_i$ values are equal?
5. How would this change if the exponent were different (e.g., cube instead of square)?

Tip:

Summation notation is a powerful way to represent repeated calculations compactly, and it's widely used in calculus, algebra, and statistics.