How to Use the BETAINV Function in Excel
Today, let’s delve into a robust statistical tool available in both Microsoft Excel and Google Sheets: the BETAINV function. This function is invaluable for calculating the inverse of the cumulative beta probability density function.
Overview and Syntax
The syntax for the BETAINV function is as follows:
BETAINV(probability, alpha, beta, [A], [B])- probability: This is the probability for which the inverse cumulative beta distribution is calculated.
- alpha: A parameter of the distribution, which must be greater than 0.
- beta: Another parameter of the distribution, which must also be greater than 0.
- A: Optional. This represents the lower bound of the x range. If omitted, the default is 0.
- B: Optional. This represents the upper bound of the x range. If omitted, the default is 1.
Examples and Use Cases
To clarify how the BETAINV function can be used, let’s review some examples.
Example 1: Basic Usage
Let’s calculate the inverse of the cumulative beta distribution for a probability of 0.3, with alpha = 2 and beta = 5:
| Formula: | =BETAINV(0.3, 2, 5) |
|---|---|
| Result: | 0.186244 |
This result indicates that the corresponding x value for a cumulative probability of 0.3 is approximately 0.186244.
Example 2: Specifying the Range
Next, we’ll calculate the inverse for a probability of 0.6, with alpha = 2, beta = 5, but this time, within the x range of 0.1 to 0.9:
| Formula: | =BETAINV(0.6, 2, 5, 0.1, 0.9) |
|---|---|
| Result: | 0.469026 |
By setting the range from 0.1 to 0.9, we adjust our calculation to this specific interval, refining our results.
Example 3: Real-World Application
Consider a scenario where you are analyzing the completion rates of an online survey. To determine the completion rate corresponding to the top 10% of survey participants, use the following inputs–alpha = 45 and beta = 20:
| Formula: | =BETAINV(0.9, 45, 20) |
|---|---|
| Result: | 0.730771 |
Hence, the completion rate for the top 10% of survey participants is approximately 73.08%.
With a clear understanding of the BETAINV function, you can now effectively apply this tool to your statistical analyses and data assessments.
More information: https://support.microsoft.com/en-us/office/betainv-function-8b914ade-b902-43c1-ac9c-c05c54f10d6c