### Question:
OddsRatioToClinicalConverter { public double getNumberNeededToTreat(Interval<Double> scale) { return 1d / getRiskDifference(scale); } OddsRatioToClinicalConverter(MetaBenefitRiskAnalysis br, OutcomeMeasure om); Interval<Double> getOddsRatio(Interval<Double> scale); Interval<Double> getRisk(Interval<Double> scale); double getRiskDifference(Interval<Double> scale); double getNumberNeededToTreat(Interval<Double> scale);  }### Answer:
@Test public void testGetNumberNeededToTreat() { Interval<Double> oddsRatio = new Interval<Double>(0.95, 1.25); Interval<Double> odds = new Interval<Double>(oddsRatio.getLowerBound() * d_baselineOdds, oddsRatio.getUpperBound() * d_baselineOdds); double riskDifference = odds.getUpperBound() / (1 + odds.getUpperBound()) - odds.getLowerBound() / (1 + odds.getLowerBound()); double expected = 1d / riskDifference; assertEquals(expected, d_orc.getNumberNeededToTreat(oddsRatio), EPSILON); }