Appendix J: Using the Linest Function in Excel
The linest function in Excel is used to find the uncertainties in the slope and y-intercept of a straight line that best fits your data. To use the linest function, follow the steps below.-
1After you enter the necessary data, highlight a two by two box of cells (see Fig.1 below).
Figure 1: Highlighting a 2 by 2 box of cells
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2Type =linest(. A help box is displayed as shown in Fig.2 below.
Figure 2: Linest function
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3Input the necessary arguments into this two by two box in the following order (see Fig. 3).
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aHighlight the y values.
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bType ,.
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cHighlight the x values.
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dType 1,1).
Figure 3: Input for the linest function
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4Press CTRL+SHIFT+ENTER. The four numbers are displayed as shown in Fig. 4.
Figure 4: Four numbers generated by the linest function
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The slope and intercept given by the Linest function is the same as that found from the equation to
the trendline (see Fig. 5 below). However, the latter does not display the uncertainties associated
with the slope and intercept.
Figure 5: Comparing outputs from linest and trendline equation