Mean, median, mode, and standard deviation
Compute the mean, median, mode, or standard deviation of a small, clean one-variable data set. Unlimited questions, five difficulty levels, and a full worked solution every time, included free with weekly lessons.
Try one
Here is the number of text messages Priya sent each day over 5 days: 14, 6, 9, 6, 14. Find the mean.
Answer: 9.8
See one solved, step by step
Here is Liam's last 6 bowling scores: 6, 20, 16, 11, 18, 17. Find the standard deviation.
📘 Worked solution
1Mean = 14.67.First find the mean -- you need it to measure how far each value is from the centre.
2Sum of squared deviations from the mean = 135.333.For each value, subtract the mean and square the result, then add them all up.
3Variance = 135.333 / 6 = 22.556.Divide by n to get the variance (the average squared distance from the mean).
4Standard deviation = √(22.556) = 4.75.Take the square root of the variance to bring the units back to the original scale.
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