What does the number mean when you have worked out the standard deviation? I.e. I have a number of 14.30525 but what does that number represent etc?
Thanks
2007-11-27 05:11:36 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
the number shows the mean deviation of the numbers from the mean value. the greater the S.D the more spread will be the data.
S.D just shows how wide spread the data is.
2007-11-27 05:18:44 · answer #1 · answered by Shahbaz 2 · 0⤊ 0⤋
You can think of it roughly as "the average amount by which things deviate from the average." It gives you a rough idea of how closely the individual numbers "cluster" around the average.
For example, let's say you give a test to 1000 people, and their average score is 70/100. Knowing the average is good, but you may want to know more. It may be that _everybody_ (or nearly everybody) scored right around 70 (say, between 68and 72). Or it may be that there was a wide range, with a lot of people scoring way below 70 and a lot scoring way above 70. The standard deviation gives you a window into that. If the standard deviation is small, it means most people scored right around 70; if it's large, it means that many people had scores significantly different from 70. (Again, "70" is just an example of an average number).
If you draw a graph, with the x-axis labeled "test score," and the y-axis labeled "number of people," the curve of the graph will usually be bell-shaped, with the highest point usually indicating the average score. The standard deviation is a rough measure of how "fat" the bell curve is.
2007-11-27 05:35:12 · answer #2 · answered by RickB 7 · 0⤊ 0⤋
Think of it as an average spread, or a measure of stability. Standard deviation: think of the word literally for a moment. Standard deviation, or sigma, is on average how far from the mean any number will be.
You must have some big numbers for a sigma of 14.3!
In certain tests it's unlikely to get a reading that is the same as the first reading. For tests like that you incorporate a sigma to gauge how far away from the mean your future readings will be.
2007-11-27 05:44:36 · answer #3 · answered by Sithlord78 5 · 0⤊ 0⤋
it means the extent it deviates from the average
2007-11-27 05:17:49 · answer #4 · answered by Jen 2 · 0⤊ 0⤋
Here ya are... some help for ya... I hope
2007-11-27 05:16:22 · answer #5 · answered by Anonymous · 0⤊ 1⤋