[Cache] Update cache-analytics.mdx (#22654)

For more info on how sampling works.

Author: nenizera

src/content/docs/cache/performance-review/cache-analytics.mdx

@@ -36,7 +36,7 @@ To add filters, under **Cache Performance**, select **Add filter**. Select **App
 
 ## Review cache status
 
-The **Requests summary** graph depicts how your traffic changes over time, such as in response to a high-traffic event or a recent configuration change. Note that the Requests summary content is based on a 10% sample of requests.
+The **Requests summary** graph depicts how your traffic changes over time, such as in response to a high-traffic event or a recent configuration change. Note that the Requests summary content is based on a 10% sample of requests. For more information on how sampling works, refer to [Understanding sampling in Cloudflare Analytics](/analytics/sampling/).
 
 **Served by Cloudflare** indicates content served by Cloudflare that did not require contacting your origin web server. **Served by Origin** indicates traffic served from the origin web server.