Statistical Formulas:
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The mean is the average of all numbers in a dataset. The standard deviation measures how spread out the numbers are from the mean. Together they describe the central tendency and variability of data.
The calculator uses these formulas:
Where:
Explanation: The mean gives the central value, while standard deviation shows how much variation exists from the mean.
Details: These are fundamental statistics used in virtually all fields of research and data analysis to summarize and understand datasets.
Tips: Enter numbers separated by commas (e.g., 1, 2, 3, 4). At least two numbers are required to calculate standard deviation.
Q1: When should I use population vs sample standard deviation?
A: Use sample standard deviation (n-1 denominator) when working with a sample of a larger population. Use population standard deviation (n denominator) when you have all data points.
Q2: What does a high standard deviation indicate?
A: A high standard deviation means data points are spread out over a wider range of values.
Q3: Can I calculate these for non-numerical data?
A: No, these calculations require numerical data that can be meaningfully averaged.
Q4: How many decimal places should I report?
A: Typically report one more decimal place than the original measurements.
Q5: What if my data contains outliers?
A: Consider using median and interquartile range instead, as mean and SD are sensitive to outliers.