Just a really dumb question here. Who told you that?!
[standard deviation of 15] implies most of my participants range from age 5 to 35? No, that's not my interpretation, based on what you've provided
Okay -- it seems that you have stated a point, above.
it is a bit pointless to look at the mean and standard deviation after all.
Am I correct in saying that?
You tell me. :???: If you were to not have looked at the mean and standard deviation, then you would not have been able to state the first point.
More seriously, I would say that the higher a standard deviation, the farther away from the mean are most of the data.
Standard deviation is what you get when you look at how far each piece of the data is from the mean and then average those numbers.
By the way, do the 30 people surveyed comprise some type of population? Are they a sample from a particular population? Were they selected randomly, as defined by statistics definition? These are considerations that one must understand, before using means or standard deviations to draw
specific conclusions.
You did not state any exercise, but, if your question pertains to an exercise that's testing your view of standard deviation, then you should go back to the textbook examples or look for more examples online AND skip over anything that does not click for you in the rest of this post.
Have you yet been introduced to the concept of "normally distributed data"? If not, it's coming. It's relevant.
Again, I do not know the content/context of your survey. Here's part of an example explaining why standard deviation is important (taken from
another website). Food for thought, before you ponder the meaning of your standard deviation result again.
If you are comparing test scores for different schools, the standard deviation will tell you how diverse the test scores are for each school.
Let's say Springfield Elementary has a higher mean test score than Shelbyville Elementary. Your first reaction might be to say that the kids at Springfield are smarter.
But a bigger standard deviation for one school tells you that there are relatively more kids at that school scoring toward one extreme or the other. By asking a few follow-up questions you might find that, say, Springfield's mean was skewed up because the school district sends all of the gifted education kids to Springfield. Or that Shelbyville's scores were dragged down because students who recently have been "mainstreamed" from special education classes have all been sent to Shelbyville.
In this way, looking at the standard deviation can help point you in the right direction when asking why information is the way it is.
So, we see that standard deviation gives us information about "how spread apart" the data are, how far "away from the mean" a majority of the data are. That's why the referenced author describes standard deviation as a kind of "average of averages". It really is, too, if you study the formula for it.
Standard deviation becomes clearer, the more examples you look at. Study a little more, and then see what you have to say about the value 15.
Cheers :cool:
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