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Appendix C – Confidence Interval Calculation
Appendix C – Confidence Interval Calculation
The Nomad Call Performance output reports employ a 90% Confidence Interval for call initiation
failure and dropped call events. The Confidence Interval allows us to report, with 90% confidence,
that the event rate for a given device will fall within the calculated range above and below the
measured value. The Confidence Interval is calculated as a function of the estimated standard
deviation of the sample proportion (% dropped calls or % call initiation failures) and the standard
normal distribution function.
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