>>10887747Ah sorry Ill try to give you a straighter answer. Figured if you ask this kind of question you would have seen the basic stuff already.
Expectation or mean value is just the average of all your data points, so where are your values for one group, so 2, 10, 6, 9 and so on and is the total number of values you have, so in your case 18 if I didnt miscount.
Standard deviation is the statistical error you can expect from your data. This is important in all kinds of ways, but in any case it gives you an interval around your average value, within which you can expect the real physical value to be. The formula for that is a bit more annoying to work with if you dont have access to something like excel or matlab, but just as straight ahead. Its defined as .
Now write for all your three columns and check if the intervals overlap. If they dont overlap at all, you have strong reason to believe that alcohol in fact does impact driving skill. If they do overlap you have to admit that either alcohol doesnt affect driving skill or that your study wasnt extensive enough, and with a bigger sample size (leading to a smaller standard deviation) the intervals wouldnt overlap, which looking at the problem is probably the case, since the values are so all over the place that the error intervals must be huge...
