CALCULATOR CATEGORY

Statistics calculators

Check whether your values represent a sample or an entire population. The sample-variance tools use n−1 in the denominator. Descriptive summaries cannot establish causation or validate how a sample was collected.

• Mean

  Find the arithmetic mean of a list of numbers.

• Median

  Find the middle value in an ordered data set.

• Standard deviation

  Measure sample dispersion around the mean.

• Sample variance

  Calculate squared spread around the sample mean.

• Range

  Find the distance between smallest and largest values.

• Z-score

  Express an observation in standard-deviation units.

• Standard error of mean

  Estimate uncertainty in a sample mean.

• Mean confidence interval

  Build a normal-approximation interval with a chosen z value.

• Event probability

  Calculate probability for equally likely outcomes.

• Weighted mean

  Calculate an average using matching weights.