STD added to numericQuestionAnalysis - #314
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Added std deviation calculations and displays on website
jmcheek
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jmcheek
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Looks good on the page, but I believe you squared the sum of the deviations rather than taking the sum the squared deviations. If you fix that, it should be good to go!
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Fixed the formula |
jmcheek
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jmcheek
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Close, but you actually calculate the mean as you looped through the numbers. Instead you'll want to move the mean calculation outside the first loop. Then loop through again and calculate the variance, then you'll divide that by numbers.length and root to get standard deviation.
| @@ -35,6 +38,11 @@ export default function NumericQuestionAnalytics({ | |||
| const number = questionResponse.answer; | |||
| total += number; | |||
| numbers.push(number); | |||
| // calculate mean for std | ||
| stdMean = ((total / numbers.length) * 100) / 100; | ||
| sdTotal += Math.pow(number - stdMean, 2); | ||
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remove line 43, and move line 44 into a separate loop
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| // Rounds standard deviation to hundredths place | ||
| standardDeviation = Math.round(standardDeviation * 100) / 100; | ||
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You'll want to calculate the mean here, your line 43 should work I believe ->
const mean = total / numbers.length
You then want to loop through and calculate the variance, and then the standard deviation
so, use your line 44 here
for (const num of numbers){
sdTotal += Math.pow(number - stdMean, 2)
}
then leave line 83 just as you have it outside the loop, and your done!
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Added std deviation calculations and displays on website
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