standard deviation program

[tink]

please can anyone help me finish this program....going mad!!
im trying to write a program that will compute the MEAN and STANDARD DEVIATION of a sequence of numbers.
sorry :-( still learning vb6 ( and struggling) thanks Tink

private Sub cboData_KeyPress(KeyAscii As integer)
DimValue As Integer
Value = Val(cboData.Text)
If KeyAscii = 13 Then
If Value >=0 Then
cboData.AddItem Value
cboData.Text = ""
Else
msgBox "sorry no negative numbers"
End If
End If
End Sub



private sub cmdMean_click()
Dim Index, sum As integer
IF cboData.ListCount>0 Then
Sum = 0
For Index = 0 To cboDataCount.ListCount - 1
Sum = Sum + Val(cboData.List(Index))
Next Index
lblResult = Sum / (cboData.ListCount)
Else
MsgBox "No Data"
End If
End Sub


Private Sub cmdStdDev_click

????????????????????????????????????????

[mlewis]

Standard deviation is simple:

Number of elements is n:

sqrt[SIGMA{x^2/n} - m^2]

x is each element in turn; m is the mean.

So your code would look like

' function to get s.d. (have mean stored in the Mean variable)
For I = 1 to cboData.ListCount
Sum = Sum + ((cboData.List(I) ^ 2) / cboData.ListCount)
Next I
Sum = Sum - (Mean^2)
SD = Sqrt(Sum)

[mlewis]

Tried to email but your username wasn't found... anyway.

My bad. Replace it with this line:

sum=sum+((Val(cboData.List(I))^2)/cboData.ListCount)

That should help.

[DerFarm]

Hey Tink, I got some table lookups and Fishers_exact for getting p-values and other stuff.

You want it?