Margin of Error Calculator

The calculator will find the margin of error from the given sample size and distribution, with steps shown.

Sample size: `n=`

Confidence level: %

standard deviation:

Distribution used:
If the population standard deviation is known or the sample size is `n>30`, normal distribution will be chosen automatically. To force another distribution, choose it explicitly.

If the calculator did not compute something or you have identified an error, or you have a suggestion/feedback, please write it in the comments below.

Solution

Your input: find the margin of error for the sample size $$$n=64$$$, standard deviation $$$\sigma=7$$$, and confidence level $$$95.0 \%$$$ using normal distribution.

First, find the critical value: $$$z_{\frac{\alpha}{2}}=1.95996398454005$$$

Next, find the standard error of the mean: $$$SE=\frac{\sigma}{\sqrt{n}}=\frac{7}{8}$$$

Finally, the margin of error is $$$ME=z_{\frac{\alpha}{2}} \cdot SE=1.95996398454005 \cdot \left(\frac{7}{8}\right) \approx 1.71496848647255$$$

Answer: $$$ME=1.71496848647255$$$