Statistical Summary
Count (N)
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Total number of valid numeric data points inputted.
Skewness
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Measures asymmetry. ~0 is normal. >0 tail is to the right. <0 tail is to the left.
Process Cap (Cp)
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Cp = (USL - LSL) / 6*Sigma. Measures potential spread relative to specs.
Actual Cap (Cpk)
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Cpk considers centering. Min(Cpu, Cpl). If Cpk < Cp, the process is off-center.
Mean (μ)
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The mathematical average of the dataset.
Median (Q2)
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The middle value separating the higher half from the lower half. Less affected by outliers.
IQR
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Interquartile Range (Q3 - Q1). Represents the middle 50% of the data. Defines the box width.
Std Dev (σ)
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Standard Deviation. Measures the dispersion or spread of the data relative to its mean.
Outliers Detected
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Real-time Interpretation
Select a process or input data to begin analysis...
Embedded Excel Formulas
Min: =MIN(A:A)
Q1 (25th %): =QUARTILE.INC(A:A, 1)
Median (Q2): =MEDIAN(A:A)
Q3 (75th %): =QUARTILE.INC(A:A, 3)
Max: =MAX(A:A)
IQR: =QUARTILE.INC(A:A,3)-QUARTILE.INC(A:A,1)
Cp: =(USL - LSL) / (6 * STDEV.S(A:A))
Cpk: =MIN((USL-AVERAGE)/(3*STDEV), (AVERAGE-LSL)/(3*STDEV))
Assume your data is in Column A.
Box & Whisker Plot Guide
- The Box represents the middle 50% of the data (IQR), bounded by Q1 (25th percentile) and Q3 (75th percentile).
- The solid line inside the box is the Median (Q2), while the dotted line represents the Mean.
- The Whiskers extend to the lowest and highest values within 1.5 * IQR from the box edges.
- Any points beyond the whiskers are mathematically classified as Outliers.
- Cp measures potential capability (spread vs limits). Cpk measures actual capability (accounts for mean centering).