**Standard Error Calculators
when population parameters are known**

These are used for investigating the theory of the sampling distributions of the sample statistics. For such investigations, we must assume more knowledge of the population than we have from samples.

- SE for a single mean: No calculator is provided
here.

Use the population standard deviation divided by the square root of the sample size.

- SE for the difference of sample means when the population
standard deviations are known. SE
sample means

Since the population standard deviations are known, the distribution is normally distributed rather than distributed as the t-distribution.

- SE for one proportion: SE
proportion

- SE for the difference of sample proportions when the
population proportions are known. SE
sample proportions

- Difference of two sample means from two independent samples: http://visualize.tlok.org/elem-stat/standard_error_diff_two_sample_means_sd.php
- One sample proportion: http://visualize.tlok.org/elem-stat/standard_error_one_proportion_sd.php
- Difference of two sample proportions from independent samples:
http://visualize.tlok.org/elem-stat/standard_error_diff_two_sample_proportions_sd.php