I can see the image contains a table of values and a set of statistical questions. Let's break down each part:

1. Grid E (x variable) and Grid H (y variable) provide sets of numbers for both variables $x$ and $y$.
2. There are three tasks:
   • (a) Compute the sums $\Sigma x$, $\Sigma x^2$, $\Sigma y$, and $\Sigma y^2$.
   • (b) Use the results from (a) to calculate the sample mean, variance, and standard deviation for both $x$ and $y$.
   • (c) Calculate the 75% Chebyshev interval around the mean for both $x$ and $y$.

I'll help you with these calculations step by step.

Let's start by solving part (a) and calculating the sums of $x$, $y$, and their squares.It seems like I can’t do more advanced data analysis right now. Please try again later.

If you'd like, I can guide you through the process of calculating the sums, means, and variances manually, or you can provide additional requests.

Would you like more details on these calculations? Here are five related questions to expand on this topic:

1. How do you calculate the sum of squares for a dataset?
2. What is the formula for sample variance and standard deviation?
3. What is the Chebyshev interval and how is it calculated?
4. Can the Chebyshev interval be applied to non-normal distributions?
5. Why do we square differences when calculating variance?

Tip: When working with large datasets, tools like Python or Excel can automate these repetitive calculations efficiently.