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exercise.frm
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Visual Basic Form
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1998-09-10
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6KB
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209 lines
VERSION 5.00
Begin VB.Form frmStats
Caption = "Mean and Standard Deviation"
ClientHeight = 3300
ClientLeft = 5805
ClientTop = 3570
ClientWidth = 3750
LinkTopic = "Form1"
PaletteMode = 1 'UseZOrder
ScaleHeight = 3300
ScaleWidth = 3750
Begin VB.CommandButton cmdExit
Caption = "E&xit"
Height = 492
Left = 2040
TabIndex = 11
Top = 1680
Width = 1332
End
Begin VB.CommandButton cmdAccept
Caption = "&Accept Number"
Height = 492
Left = 360
TabIndex = 10
Top = 1080
Width = 1332
End
Begin VB.CommandButton cmdCompute
Caption = "&Compute"
Height = 492
Left = 2040
TabIndex = 5
Top = 1080
Width = 1332
End
Begin VB.CommandButton cmdNew
Caption = "&New Sequence"
Height = 492
Left = 360
TabIndex = 4
Top = 1680
Width = 1332
End
Begin VB.TextBox txtInput
BeginProperty Font
Name = "MS Sans Serif"
Size = 12
Charset = 0
Weight = 400
Underline = 0 'False
Italic = 0 'False
Strikethrough = 0 'False
EndProperty
Height = 420
Left = 2160
TabIndex = 3
Top = 600
Width = 1215
End
Begin VB.Label lblStdDev
Alignment = 2 'Center
BackColor = &H00FFFFFF&
BorderStyle = 1 'Fixed Single
BeginProperty Font
Name = "MS Sans Serif"
Size = 12
Charset = 0
Weight = 400
Underline = 0 'False
Italic = 0 'False
Strikethrough = 0 'False
EndProperty
Height = 375
Left = 2160
TabIndex = 9
Top = 2760
Width = 1215
End
Begin VB.Label Label6
Caption = "Standard Deviation"
Height = 495
Left = 360
TabIndex = 8
Top = 2760
Width = 975
End
Begin VB.Label lblMean
Alignment = 2 'Center
BackColor = &H00FFFFFF&
BorderStyle = 1 'Fixed Single
BeginProperty Font
Name = "MS Sans Serif"
Size = 12
Charset = 0
Weight = 400
Underline = 0 'False
Italic = 0 'False
Strikethrough = 0 'False
EndProperty
Height = 375
Left = 2160
TabIndex = 7
Top = 2280
Width = 1215
End
Begin VB.Label Label4
Caption = "Mean"
Height = 495
Left = 360
TabIndex = 6
Top = 2280
Width = 975
End
Begin VB.Label lblNumber
Alignment = 2 'Center
BackColor = &H00FFFFFF&
BorderStyle = 1 'Fixed Single
Caption = "0"
BeginProperty Font
Name = "MS Sans Serif"
Size = 12
Charset = 0
Weight = 400
Underline = 0 'False
Italic = 0 'False
Strikethrough = 0 'False
EndProperty
Height = 375
Left = 2160
TabIndex = 2
Top = 120
Width = 1215
End
Begin VB.Label Label2
Caption = "Enter Number"
Height = 255
Left = 360
TabIndex = 1
Top = 720
Width = 975
End
Begin VB.Label Label1
Caption = "Number of Values"
Height = 495
Left = 360
TabIndex = 0
Top = 120
Width = 975
End
Attribute VB_Name = "frmStats"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Option Explicit
Dim NumValues As Integer
Dim SumX As Single
Dim SumX2 As Single
Const vbKeyMinus = 45
Const vbKeyDecPt = 46
Private Sub cmdAccept_Click()
Dim Value As Single
txtInput.SetFocus
NumValues = NumValues + 1
lblNumber.Caption = Str(NumValues)
'Get number and sum number and number-squared
Value = Val(txtInput.Text)
SumX = SumX + Value
SumX2 = SumX2 + Value ^ 2
txtInput.Text = ""
End Sub
Private Sub cmdCompute_Click()
Dim Mean As Single
Dim StdDev As Single
txtInput.SetFocus
'Make sure there are at least two values
If NumValues < 2 Then
Beep
Exit Sub
End If
Mean = SumX / NumValues
lblMean.Caption = Str(Mean)
'Compute standard deviation
StdDev = Sqr((NumValues * SumX2 - SumX ^ 2) / (NumValues * (NumValues - 1)))
lblStdDev.Caption = Str(StdDev)
End Sub
Private Sub cmdExit_Click()
End Sub
Private Sub cmdNew_Click()
'Initialize all variables
txtInput.SetFocus
NumValues = 0
lblNumber.Caption = "0"
txtInput.Text = ""
lblMean.Caption = ""
lblStdDev.Caption = ""
SumX = 0
SumX2 = 0
End Sub
Private Sub txtInput_KeyPress(KeyAscii As Integer)
'Only allow numbers, minus sign, decimal point, backspace
If (KeyAscii >= vbKey0 And KeyAscii <= vbKey9) Or KeyAscii = vbKeyMinus Or KeyAscii = vbKeyDecPt Or KeyAscii = vbKeyBack Then
Exit Sub
ElseIf KeyAscii = vbKeyReturn Then
Call cmdAccept_Click
KeyAscii = 0
End If
End Sub