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Using the Action Menu

upoissonPDf

Function: Returns the probability in a Poisson distribution that the success will occur on a specified trial.

Syntax: poissonPDf (x, μ [ ) ]

Example: To determine the Poisson probability when x = 10, μ = 6

Menu Item: [Action][Distribution][poissonPDf]

For more information, see “Poisson Distribution Probability” on page 7-11-17.

upoissonCDf

Function: Returns the cumulative probability in a Poisson distribution that the success will occur on or before a specified trial.

Syntax: poissonCDf (x, μ [ ) ]

Example: To determine the Poisson cumulative probability when x = 3, μ = 2.26

Menu Item: [Action][Distribution][poissonCDf]

For more information, see “Poisson Cumulative Distribution” on page 7-11-18.

uinvPoissonCDf

Function: Returns the minimum number of trials of a Poisson cumulative probability distribution for specified values.

Syntax: invPoissonCDf (prob, μ [ ) ]

Important!

When executing the invPoissonCDf function the calculator uses the specified prob value and the value that is one less the prob value minimum number of significant digits (*prob value) to calculate minimum number of trials values. The results are assigned to the system variables xInv (calculation result using prob) and *xInv (calculation result using *prob). The invPoissonCDf function always returns the xInv value only. However, when the xInv and *xInv values are different, the warning message shown below appears showing both values.

The calculation results of invPoissonCDf are integers. Accuracy may be reduced when the first argument has 10 or more digits. Note that even a slight difference in calculation accuracy affects calculation results. If a warning message appears, check the displayed values.

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