Use the strip endpoints as a quick reasonableness check before trusting the
centroid arithmetic. In this toy cluster the hits span 1 to 2 meters, so the
5/4 meter centroid must stay between them; real reconstruction also has finite
strip pitch, alignment offsets, thresholds, and resolution limits.
The centroid must remain inside the checked cluster span. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
The span comes from the endpoint positions
The cluster endpoints are 1 meter and 2 meters.
1m≤x≤2m
The centroid must lie inside that span
The centroid 5 over 4 meters is between the endpoints.