Unformatted text preview: Y = a + b ln(X) All X values > zero Exponential Y = a bx All Y values > zero Power Y=aX Restrictions b All X and Y values > zero The statistical results are calculated using transformed values:
The linear model uses X and Y.
The logarithmic model uses ln(X) and Y.
The exponential model uses X and ln(Y).
The power model uses ln(X) and ln(Y).
The calculator determines the values for a and b that create the line or
curve that best fits the data. Correlation Coefficient
The calculator also determines r (the correlation coefficient) which
measures the goodness of fit of the equation with the data.
In general, the closer r is to 1 or 1, the better the fit; the closer r is to zero,
the worse the fit. Entering Data
Pressing
lets you enter and view up to 50 data points. The
Statistics worksheet stores the values you enter until you clear the
worksheet or change the values. Therefore, you may not need to do all the
steps in the procedures on these pages each time you perform a Statistics
calculation. Entering Data Points
1. Press
worksheet. to select the dataentry portion of the Statistics X01 is displayed, along with any previous value. 2. Press to clear the worksheet. 3. Key in a value for X01 and press . If you are entering onevariable data, X01 is the first data point.
If you are entering twovariable data, X01 is the first X value. Chapter 6: Using the Statistics Worksheet 51 4. Press to display the Y01 variable. Key in a value for Y01 and press
. If you are entering onevariable data, you can enter the number of
times the X value occurs (frequency). The default value is 1.
If you are entering twovariable data, enter the first Y value.
5. Press to display the next X variable. 6. Repeat steps 3 through 5 until all of the data points are entered. Viewing the Data Points
As with other worksheets, you can move up and down through the dataentry portion of the Statistics worksheet by pressing
or . Editing Data
Pressing
also lets you insert or delete data points. You may not
need to do all the steps in th...
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 Summer '09
 PETRY

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