Say I have the following list of numbers, each corresponding to a single day:
list = [1, 6, 7, 12, 5]
I can calculate the daily, rolling standard deviations between each as:
stds = [NaN, 3.54, 0.71, 3.54, 4.95]
Is it now possible to calculate the standard deviation across all values of list, using only the values of stds?
The rolling pairwise standard deviations don't give you enough information to get the total standard deviation. The two lists $$[0,1,0,1]\quad \&\quad [0,1,2,3]$$ both have the pairwise standard deviations $$\Big[\frac 1{\sqrt 2},\,\frac 1{\sqrt 2},\,\frac 1{\sqrt 2}\Big]$$
But the total standard deviation of the first is $.577$ and the standard deviation of the second is $1.29$.
Note: in all cases we are using the sample standard deviation (i.e. we divide by $n-1$ not $n$).