Standard deviation

Cards (5)

How is standard deviation better than the range?
It uses all the observations, and is less affected by the outliers.
What does a 'thin' curve mean in SD?
It means that most values remain close to the average, and the standard deviation is small.
What does a 'wide' curve mean in SD?
A 'wide' curve means that there is a wider spread of values about the mean, and the standard deviation is large.
How to you calculate standard deviation?
.
$SD=$ $\sqrt{\frac{\left(x-X̄\right)^2}{n-1}}$
How do you describe the SD results?
There is no overlap in the (± 2 SD) bars.
This indicates that the differences in the means is likely/unlikely to be due to chance. The differences are/are not significant.