159k views
0 votes
How large a sample should be selected to provide a 95% confidence interval with a margin of error of 7?

User Jwinn
by
8.0k points

1 Answer

3 votes

Final answer:

To determine the sample size needed to provide a 95% confidence interval with a margin of error of 7, use the formula: Sample size = (Z^2 * (p * (1-p))) / (E^2). Plugging in the values, the sample size would be approximately 106.

Step-by-step explanation:

To determine the sample size needed to provide a 95% confidence interval with a margin of error of 7, you need to use the formula:

Sample size = (Z^2 * (p * (1-p))) / (E^2)

Where:

  • Z: The Z-score corresponding to the desired confidence level. For a 95% confidence level, the Z-score is approximately 1.96.
  • p: An estimate of the proportion from the population. Since the proportion is not mentioned in the question, you can assume a conservative estimate of 0.5.
  • E: The margin of error, which is 7 in this case.

Plugging in these values into the formula, the sample size would be approximately 106.

User John Lemp
by
7.9k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories