To solve the given expression:

$\sqrt{\frac{\sum(4282 - 428.2)^2}{9}}$

Let's break it down step by step:

Step 1: Simplify inside the summation

You are summing $(4282 - 428.2)^2$, but since there is no indication of multiple terms in the summation, we can assume this is applied to a set of values. However, without specific values given, let's first calculate this difference:

$4282 - 428.2 = 3853.8$

Step 2: Square the result

Now, square $3853.8$:

$3853.8^2 = 14852520.44$

Step 3: Divide by 9

Now divide the squared result by 9:

$\frac{14852520.44}{9} = 1650279.493$

Step 4: Take the square root

Finally, take the square root of $1650279.493$:

$\sqrt{1650279.493} \approx 1284.67$

So the value of the given expression is approximately 1284.67.

Would you like to see more details or clarifications? Here are some related questions:

1. What is the significance of the summation symbol in statistical contexts?
2. How do you interpret this formula as a standard deviation calculation?
3. Can this expression represent a variance calculation?
4. How would adding more terms to the summation affect the result?
5. How do you handle summations involving variable numbers of terms?

Tip: Always carefully distinguish between the different steps in summations and apply proper operations at each stage!