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Count Frequency

When your paired X/Y data is pre-aggregated with counts, use a Count column as the frequency. Quantum XL expands the dataset by the count value, weighting the regression so that frequently observed data points have more influence on the fitted line.

Goal

Create a scatter plot with weighted regression from pre-aggregated hours-vs-output data.

Sample Data

Download ScatterPlot_CountFrequency.xlsx

Excel Protected View

When you open downloaded files, Excel displays a Protected View warning. You must click Enable Editing before you can use Quantum XL with the file.

Alternatively, you can copy the sample data from the table below and paste it directly into a new Excel workbook.

Hours	Output	Frequency
2.0	15.3	5
4.0	28.7	8
6.0	42.1	12
8.0	55.8	10
10.0	68.4	7
3.0	21.5	6
5.0	35.2	9
7.0	49.0	11
9.0	62.3	4
1.0	8.1	3

There are 10 rows with frequencies totaling 75 observations. The frequency column tells Quantum XL how many times each X/Y pair was observed. Points with higher frequency have more influence on the regression line.

Steps

1. Launch the analysis

   From the Excel ribbon, select QXL Stat Tools → Analysis Tools → Scatter Plot.

2. Select your data

   Select cells A1:C11 (the header row plus all 10 data rows).

3. Configure the analysis

   In the Scatter Plot dialog:

   • X Columns: "Hours" should be checked
   • Y Columns: "Output" should be checked
   • Frequency Data: Check "Frequency"
   • Regression: "Linear" should be selected

   Click Finish to generate the chart.

Result

Quantum XL creates a scatter plot of Hours vs Output with a weighted linear regression line. The count in the statistics shows 75 (the expanded total), not 10 rows. The regression coefficients and R² are computed on the frequency-weighted data, giving more influence to data points that were observed more frequently.