What is the first step to be performed when computing Σ(X + 2)2?

What is the first step to be performed when computing Σ(X + 2)2?

• A. Square each value
• B. Add 2 points to each score
• C. Sum the squared values
• D. Sum the (X +2) values

Answer: (B)

When you see a sum of squared transformed values, you must apply the inside operation to each data point first. So the first step is to add 2 to every X value, forming X+2 for each observation. Only after that do you square each result and then sum. For example, with X = 1, 3, 5, the first step gives 3, 5, 7; squaring yields 9, 25, 49; summing gives 83.

When you see a sum of squared transformed values, you must apply the inside operation to each data point first. So the first step is to add 2 to every X value, forming X+2 for each observation. Only after that do you square each result and then sum. For example, with X = 1, 3, 5, the first step gives 3, 5, 7; squaring yields 9, 25, 49; summing gives 83.