The age when Meanobs = SDobs* for weight or length increment and the probability (%) of seeing no growth at age 12 months, depending on the amount of noise in the measurement. and the time interval.
| Interval size | Age (months) when Meanobs=SDobs* | Chance of no growth at 12 months | |||||
| 2 weeks | 4 weeks | 8 weeks | 2 weeks | 4 weeks | 8 weeks | ||
| Weight | SD as observed | 10 | 12 | >12 | 21% | 15% | 6% |
| SD with extra noise | 6 | 10 | >12 | 30% | 20% | 10% | |
| Length | SD as observed | >12 | >12 | >12 | 12% | 6% | 1% |
| SD with extra noise | 5 | 12 | >12 | 24% | 16% | 3% | |
*When chance of no growth reaches 16%.
Meanobs, observed mean; SDobs, observed SD.