Need helps please guys helps 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.

Find the value of 1715⋅211.though these numbers aren't quite as nice as the ones from the example or the previous part, the procedure is the same, so this is really no more difficult. give the numerator followed by the denominator, separated by a comma.

Given the parent function of [tex]f(x)=x^4[/tex], what change will occur when the function is changed to [tex]f(\frac{1}{2} x)[/tex]?