In triangulation, if the value R exceeds a threshold, a new baseline should be computed. What is that threshold?

• A. 80
• B. 60
• C. 100
• D. 120

Answer: (A)

In triangulation, R is a quality control measure that flags how much the measured data for a baseline disagree with its computed value, usually expressed as a residual or misfit relative to expected variability. When this misfit stays below a certain limit, the baseline is considered trustworthy. If R grows beyond that limit, the discrepancy is large enough that the baseline could be biased or propagates errors through the network, so you recompute the baseline using additional observations or a refined adjustment.

The threshold value of 80 is chosen as a practical balance: it’s high enough to avoid unnecessary recalculations for normal random fluctuations, but low enough to catch genuinely inconsistent data that would degrade overall accuracy if left unaddressed. Choosing smaller numbers would trigger too many recomputations, while larger numbers could let problematic baselines slip by.