Help me please? I have to turn in math i need help right now please

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.

In the triangles, bc =de and ac fe.if the mzc is greater than the mze, then ab isdfelth

Which expression demonstrates the use of the commutative property of addition in the first step of simplifying the expression (-1+i)+(21+5i)+0