In the expression ΣX^2, what is the first operation performed on each X value?

• A. Square each value
• B. Take the square root of each value
• C. Multiply all values together
• D. Add the values directly

Answer: (A)

The expression ΣX^2 means you transform each value by squaring it, then add all those squared values together. In other words, for every X in the data, you first compute X^2, and only after that do you sum all those squared results. This is why the first operation on each X is squaring. It’s not taking a square root, not multiplying the X values together, and not adding the raw X values directly. This approach underlies the concept of sum of squares, which is fundamental in analyses like variance.