Margin of Error Statistics Example 4

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Example 4

hard
If the confidence level is increased from 90% to 99% while the sample size and variability stay the same, what happens to the margin of error?

Solution

  1. 1
    Step 1: A higher confidence level uses a larger critical value, which makes the confidence interval wider.
  2. 2
    Step 2: Therefore, the margin of error increases when the confidence level increases.

Answer

The margin of error increases.
There is a tradeoff between confidence and precision. To be more confident that an interval captures the true parameter, we usually need a wider interval and therefore a larger margin of error.

About Margin of Error

The margin of error is the maximum expected difference between a sample statistic and the true population parameter, typically expressed as a plus-or-minus value. It equals half the width of a confidence interval and decreases as sample size increases.

Learn more about Margin of Error →

More Margin of Error Examples

Example 1 hard

A poll of 400 voters found 55% support a policy. Calculate the margin of error for a 95% confidence

Example 2 hard

How does quadrupling the sample size affect the margin of error?

Example 3 hard

A 95% CI for a mean is [formula]. What is the margin of error, and what would it be if the sample si

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