Pls help this is very easy

Describe in detail how you would construct a 95% confidence interval for a set of 30 data points whose mean is 20 and population standard deviation is 3. be sure to show that you know the formula and how to plug into it. also, clearly state the margin of error.

Solve the equation using the given values: x= -2.5; y= -7.51. 2xy + 2x²

Look at the following graph of the given equation. determine whether the equation is a function. explain why or why not.