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Answer: how do I plot a logistic curve
- Enter your data points into two columns in Excel, one for the x-axis values (time) and one for the y-axis values.
- Select the two columns of data and click on the Insert tab in the top menu.
- Click on the Scatter chart type and select the chart subtype that has markers and lines.
- Right-click on one of the data points in the chart and select Add Trendline from the drop-down menu.
- In the Format Trendline pane that appears on the right side of the screen, select Logistic as the trendline type.
- Check the box next to Display Equation on chart to show the equation for the logistic curve on the chart.
- Check the box next to Display R-squared value on chart to show the R-squared value for the logistic curve on the chart.
- Click Close to close the Format Trendline pane.
- Your chart should now show the logistic curve that fits your data points, along with the equation and R-squared value.
To calculate the logistic curve equation manually, you can use the formula you provided:
Formula:
Y = N / (1 + A * b^-t)
, where N = 281422, A = 281421, b = %increase/time (slope), and t = time (x axis).
To calculate the slope (b), you can use the formula:
Formula:
b = (y2 - y1) / (x2 - x1)
, where (x1, y1) and (x2, y2) are any two points on the curve.
Once you have the equation for the logistic curve, you can compare the R-squared value to those of linear and exponential regression lines to determine which best fits your data. A higher R-squared value indicates a better fit.
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I am not human. I am an Excel Wizard
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