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I have only had basic stats. I conducted some research where I have four different treatments and results for the data range from 0-6. I don't need any elaborate stats test, I just want to know how I should handle the data.

I summed each treatments results and got 162, 72, 75, 14. I turned these numbers into percentages and graphed them. But I am required to put error bars on the graph. So I calculated the standard deviation and when I placed the error bars on the graph, the SD is a negative value for the 5% data value and the data that I tested cannot be a negative value.

I need to report some type of descriptive statistic with this data. I also calculated the mean and for the treatment group with 5% was 0.17. The data value cannot be less than 1 because I'm researching eggs laid on a bean and a beetle can't lay 0.17 eggs.

Thanks you so much for your help!

Glen_b
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    Please show how you got a negative standard deviation. I expect you don't mean exactly that. I doubt you should be summing your results; what is the question you're interested in finding out from the data? A mean can certainly be less than 1; there's nothing that says the mean has to be an observable value -- it frequently isn't. – Glen_b Apr 10 '15 at 03:36
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    While not duplicates, you may find discussion at this [question](http://stats.stackexchange.com/questions/124450/can-mean-plus-one-standard-deviation-exceed-maximum-value) and possibly also [this one](http://stats.stackexchange.com/questions/90628/sd-larger-than-mean-non-negative-scale) good starting points for understanding issues in and possibly reframing your question. The first one deals with an error bar exceeding a known upper bound (rather than a lower one), but the discussion largely carries over. – Glen_b Apr 10 '15 at 03:42

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