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Nana
Nana
Date Posted: 3 years ago
Views: 432

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David Tan
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24 answers (Tutor Details)
1st
Qn 2 working.
For new standard deviation, use formula from this link called Welford's method.

https://math.stackexchange.com/questions/775391/can-i-calculate-the-new-standard-deviation-when-adding-a-value-without-knowing-t

https://jonisalonen.com/2013/deriving-welfords-method-for-computing-variance/
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David Tan
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Q3 answer:

Refer to link on how to convert percentile to index and vice versa, https://www.dummies.com/education/math/statistics/how-to-calculate-percentiles-in-statistics/