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EXPONDIST
Returns the exponential distribution. Use EXPONDIST to model the time between events, such as how long an automated bank teller takes to deliver cash. For example, you can use EXPONDIST to determine the probability that the process takes at most 1 minute.
Syntax
EXPONDIST(x,lambda,cumulative)
X is the value of the function.
Lambda is the parameter value.
Cumulative is a logical value that indicates which form of the exponential function to provide. If cumulative is TRUE, EXPONDIST returns the cumulative distribution function; if FALSE, it returns the probability density function.
Remarks
- If x or lambda is nonnumeric, EXPONDIST returns the #VALUE! error value.
- If x < 0, EXPONDIST returns the #NUM! error value.
- If lambda ≤ 0, EXPONDIST returns the #NUM! error value.
- The equation for the probability density function is:
- The equation for the cumulative distribution function is:
Example
The example may be easier to understand if you copy it to a blank spreadsheet.
How?
- Create a blank spreadsheet.
- Select the example in the Help topic.
Selecting an example from Help
- Press CTRL+C.
- In the spreadsheet, select cell A1, and press CTRL+V.
- To switch between viewing the formula that returns the result and the result in the cell, select the cell and press F2 and then ENTER, or click Commands and Options on the spreadsheet toolbar, click the Formula tab, and look in the Formula in active cell (active cell) box.
| Data | Description |
|---|---|
| 0.2 | Value of the function |
| 10 | Parameter value |
| Formula | Description (Result) |
| =EXPONDIST(A2,A3,TRUE) | Cumulative exponential distribution function (0.864665) |
| =EXPONDIST(0.2,10,FALSE) | Probability exponential distribution function (1.353353) |