Population Parameters

Question

You conduct a survey and find that 422 seniors out of 813 plan to go to college. What is the margin of error for your survey? Give your answer as a whole percent. Remember to include your % sign.

Answer 1

In the absence of a confidence level: Margin of error = 1/sqrt(sample size).

Using a confidence level: z* * sqrt(p * (1-p)/sample size), where p = 422/813 and z* is the critical z value corresponding to your confidence level (e.g, if confidence level is 95%, z* = 1.96)