How to determine the lower and upper boundary for a sampling distribution?

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.

For what value of x does 4x = (1/8) x + 5?

What is the prime factorization of 23 ?me with this question