updated docs

Signed-off-by: amanycodes <amanycodes@gmail.com>

Author: amanycodes

docs/querying/functions.md

@@ -415,7 +415,7 @@ annotation, you should find and remove the source of the invalid data.
 ## `histogram_stddev()` and `histogram_stdvar()`
 
 `histogram_stddev(v instant-vector)` returns the estimated standard deviation
-of observations for each histogram sample in `v`, based on the geometric mean
+of observations for each histogram sample in `v`, based on the arithmetic mean
 of the buckets where the observations lie. Float samples are ignored and do not
 show up in the returned vector.
 

web/ui/mantine-ui/src/promql/functionDocs.tsx

@@ -1267,7 +1267,7 @@ const funcDocs: Record<string, React.ReactNode> = {
 
       <p>
         <code>histogram_stddev(v instant-vector)</code> returns the estimated standard deviation of observations in a native
-        histogram, based on the geometric mean of the buckets where the observations lie. Samples that are not native
+        histogram, based on the arithmetic mean of the buckets where the observations lie. Samples that are not native
         histograms are ignored and do not show up in the returned vector.
       </p>