I dont understand what to do on these two questions. Please show work and explain so I can apply to my other homework prob

3. Find the margin of error for the 95% confidence interval used to estimate the population proportion with n = 163 and x = 96.

Solution:

4. Construct the confidence interval for question 3.

6.Under what circumstances do we need to use a Student's t-distribution to calculate the population mean?

7.Find the critical value for t_/2corresponding to n = 12 and 95% confidence level.

I need to be able to do this on my own forquestions and of course on the exam in the future and I am stumped