Statistical Data Set Generator

What is the statistical data set generator?

The Nalgoritmo statistical data set generator creates random sets of numbers so you can practice descriptive statistics by hand. Choose how many values you want, the range, whether they are whole numbers or decimals, the order and whether the set is a population or a sample, then work out each statistic and check your answers.

It was made for students and teachers of statistics, mathematics, data analysis and research methods who want quick, unlimited practice with real calculations.

Features

• Configurable data sets: from 3 to 100 values, with a minimum and maximum value, whole numbers or decimals, in random, ascending or descending order.
• Eight statistics: mean, mode, median, range, mean absolute deviation, variance, standard deviation and coefficient of variation.
• Population or sample: variance and standard deviation divide by N for a population and by n − 1 for a sample, and the coefficient of variation follows; population is the default.
• Show answer: the button in each field shows the correct value and says whether your answer is correct or incorrect.
• Show result and answer key: show the correct value in every field at once, or every statistic together in the answer key.
• Copy values: copies the data set to paste into a spreadsheet or calculator.

How to use

1. Set the options: number of values, minimum and maximum value, type of value, order and statistics (population or sample).
2. Click “Generate data set”.
3. Work out the statistics on your own and type your answers under “Your calculations”.
4. Click “Show answer” in a field to check it, or “Show result” to see every answer.

Frequently asked questions

What is the difference between population and sample statistics?

For a population, the variance divides the sum of the squared deviations by N, the number of values: σ² = Σ(x − μ)² / N. For a sample, it divides by n − 1: s² = Σ(x − x̄)² / (n − 1). The standard deviation is the square root of the variance, and the coefficient of variation is the standard deviation divided by the mean, times 100. The mean, mode, median, range and mean absolute deviation are the same in both cases.

How are the answers checked?

Type numbers with a comma or a point as the decimal separator, using 2 decimal places. An answer is correct when it is within 0.01 of the exact value; for the mean absolute deviation, variance, standard deviation and coefficient of variation, a difference of up to 0.5% is also accepted, to allow for rounding in the intermediate steps. For the mode, separate several values with semicolons (for example 3; 8) or write “No mode” when no value repeats.

What is the mean absolute deviation?

It is the mean of the distances between each value and the mean: MAD = Σ|x − x̄| / n. It is also called the mean deviation.

When does a data set have no mode?

When no value appears more than once. If two or more values share the highest frequency, all of them are modes.

How many values can a data set have?

From 3 to 100 values, with any minimum and maximum, as whole numbers or as decimals with two decimal places.