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WEIBULL

The WEIBULL function returns the Weibull distribution, which is a continuous probability distribution that is often used to model failure rates of systems over time. The function takes four arguments: x, which is the value at which to evaluate the distribution; shape, which is the shape parameter of the distribution; scale, which is the scale parameter of the distribution; and cumulative, which is a logical value indicating whether to return the cumulative distribution function (TRUE) or the probability density function (FALSE).

Usage

Use the WEIBULL formula with the syntax shown below, it has 4 required parameters:

=WEIBULL(x, shape, scale, cumulative)
Parameters:
  1. x (required):
    The value at which to evaluate the distribution.
  2. shape (required):
    The shape parameter of the distribution. Must be greater than 0.
  3. scale (required):
    The scale parameter of the distribution. Must be greater than 0.
  4. cumulative (required):
    A logical value indicating whether to return the cumulative distribution function (TRUE) or the probability density function (FALSE).

Examples

Here are a few example use cases that explain how to use the WEIBULL formula in Google Sheets.

Calculating probability of failure

The WEIBULL function can be used to model the failure rate of a system and calculate the probability that the system will fail within a certain time frame.

Analyzing reliability data

The WEIBULL function is often used in reliability engineering to analyze data on the failure rates of products over time.

Fitting a distribution to data

The WEIBULL function can be used to fit a Weibull distribution to a set of data and evaluate how well the distribution fits the data.

Common Mistakes

WEIBULL not working? Here are some common mistakes people make when using the WEIBULL Google Sheets Formula:

Using a negative value for shape or scale

The shape and scale parameters of the Weibull distribution must be greater than 0. If you use a negative value for either parameter, the WEIBULL function will return an error.

Using the wrong parameter order

Make sure you provide the WEIBULL function with the correct parameter order: x, shape, scale, cumulative. If you mix up the order of the parameters, the function will return an error.

The following functions are similar to WEIBULL or are often used with it in a formula:

  • NORMDIST

    The NORMDIST function in Google Sheets calculates the normal distribution for a specified value, mean, and standard deviation. It returns the probability of a value occurring within a specified range of a normal distribution. It is commonly used in statistics, finance, and science to analyze data and make predictions.

  • GAMMADIST

    The GAMMADIST function calculates the gamma distribution for a given set of parameters. The gamma distribution is a continuous probability distribution that is often used in statistics. It is commonly used to model the time between events. The function returns the probability density function or the cumulative distribution function for a given set of parameters.

  • EXPONDIST

    The EXPONDIST function calculates the probability of an event occurring at a specific time, assuming that the events follow an exponential distribution. It is commonly used in reliability analysis to model the time between failures of a system.

Learn More

You can learn more about the WEIBULL Google Sheets function on Google Support.