Hey guys
I had the worst statistics teacher ever in grad school so I'll try to make this painless
A standard deviation is how far from the average you move
All you have to know for this problem is that when you go one standard deviation down from the mean you subtract one standard deviation from the mean, that's it
The mean is \(\frac{5}{6}\)
One standard deviation is \(\frac{1}{3}\)
Let's make the denominator 6 because the mean has 6 in the denominator
\(\frac{1}{3} = \frac{2}{6}\)
One standard deviation is \(\frac{2}{6}\)
So what value is 2.5 standard deviations (SD) from the mean?
Mean - One SD =
\(\frac{5}{6} - \frac{2}{6} = \frac{3}{6}\)
Now let's subtract another one:
\(\frac{3}{6} - SD = \frac{3}{6} - \frac{2}{6} = \frac{1}{6}\)
Now we have to subtract half of a standard deviation
What is one half of \(\frac{2}{6}\)?
\(\frac{2}{6} * \frac{1}{2} = \frac{2}{12} = \frac{1}{6}\)
\(\frac{1}{6} - \frac{SD}{2}\) = \(\frac{1}{6} - \frac{1}{6}\) = 0
The answer is (A)
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