Someone help what’s the correct one???

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 cot x if sin x cot x csc x = √2

The length of an intercepted arc of a central angle of a circle is 4 cm. if the radius of the circle is 5 cm what is the measurement of the central angle to the nearest whole degree