What's the area of this parallelogram?

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.

The roots of the function f(x) = x2 – 2x – 3 are shown. what is the missing number?

Determine the area of a triangle with (see picture below)