Standard deviation to count

#1

I want to calculate the standard deviation for columns called time and errors… Could someone help me? Thank you very much.

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#2

The easiest way to create two extra formula columns to calculate the (X - Average(X))^2 part for time and errors respectively, and then calculate standard deviation as SquareRoot(Sum(…) / Count(X)).

See here:

P.S. “Mean” is just another word for average.

#3

@Paul_Danyliuk
Thank you very much. Taking into account the standard deviation, I have created an indicator that informs about the impulsiveness of the person. The higher the number, the greater the impulsivity. Can you help me create a conditional formula, which will determine the color of the person depending on the intensity of impulsivity?

#4

You can use conditional formatting to color the rows of the table. Formulas will be simple — like Impulsiveness >= -1 AND Impulsiveness < 0, and you can make multiple formats for different ranges and apply different colors.

If you want something else, like displaying a value in a row based on impulsiveness, you can use SwitchIf, e.g. SwitchIf(Impulsiveness < -5, "Red", Impulsiveness < -1, "Orange", Impulsiveness < 1, "Yellow", Impulsiveness < 5, "Light green", "Green")

#5

Thank you, but the point is that my impulsivity index does not have a fixed scale, e.g. from 1 to 5, but it is changeable and its distribution is different depending on the sample of respondents. That is, the maximum result on the impulsivity index can be 5 in one sample but 2 in another. That means that the maximum result depends on the test sample. I do not know if I expressed myself well.

#6

Well, you can always calculate Min and Max, and along with the average and standard deviation, use those to determine your ranges.

I believe you want something like mean - stddev, mean - 2*stddev etc, as in Bell curve?

You can also calculate each row’s rank based on the impulsiveness value, and then apply e.g. red color to the first 20% of rows, orange color to the second 20% etc.

FYI coda already has percentile functions, see: https://coda.io/formulas#Percentile and PercentileRank. But I think those don’t take stddev into account.

I don’t know what exactly you need, but given these formulas and approaches, I believe you can figure it out :wink:

1 Like
#7

Thank you very much. I will try and do what I can to solve these issues but it is not an easy task for a novice in Coda :blush: Thank you again.