text: export function getCurrentProbability(state) {
  	return state.interval.probability;
  }
  
  export function getResponseTime(prevStats, time) {
  	return time - prevStats.flashcardShownTime;
  }
  
  export function getSampleMean(prevStats, responseTime, increase = 1) {
  	return (
  		(responseTime + prevStats.sumResponseTime) /
  		(prevStats.numResponses + increase)
  	);
  }
  
  export function getResponseDeviation(prevStats, responseTime) {
  	return Math.pow(responseTime - prevStats.sampleMean, 2);
  }
  
  export function getSampleVariance(prevStats, currentVariance) {
  	const solution =
  		prevStats.numResponses > 1
  			? (prevStats.sumTestVariance + currentVariance) / prevStats.numResponses
  			: 6250000;
  	if (solution >= Number.MAX_VALUE) {
  		alert("Variance overflow.  Need to fix this");
  	}
  	return solution;
  }
  
  export function getAlpha(sampleMean, sampleVariance) {
  	return Math.pow(sampleMean, 2) / sampleVariance;
  }
  
  export function getBeta(sampleMean, sampleVariance) {
  	return sampleMean / sampleVariance;
  }
  