The NORMINV function is a powerful tool in Google Sheets designed to help users determine the inverse of the normal distribution. This function is particularly useful for statistical analyses, enabling the retrieval of a value that corresponds to a specific probability within a normal distribution, defined by its mean and standard deviation.

Syntax

NORMINV(probability, mean, standard_deviation)

• probability: The probability for which you want to find the corresponding value in the normal distribution.
• mean: The arithmetic mean of the normal distribution.
• standard_deviation: The standard deviation of the normal distribution, which indicates the dispersion of the dataset.

Example #1

=NORMINV(0.95, 100, 15)

This function call calculates the value at the 95th percentile of a normal distribution with a mean of 100 and a standard deviation of 15. The resulting value may be 125.

Example #2

=NORMINV(0.5, 50, 10)

In this instance, the function determines the median value of a normal distribution with a mean of 50 and a standard deviation of 10, which will yield 50 as the result.

Example #3

=NORMINV(0.05, 70, 20)

This call computes the value at the 5th percentile for a normal distribution with a mean of 70 and a standard deviation of 20, yielding a result around 44.

Error handling

• NUM! This error indicates that the probability is less than 0 or greater than 1, which is outside the acceptable range for a cumulative distribution function.
• VALUE! This occurs when one of the arguments provided is not a number, leading to an invalid input for the function.
• DIV/0! This happens if the standard deviation is set to zero, making the calculation mathematically undefined.

Conclusion

In summary, the NORMINV function is an essential statistical tool in Google Sheets, allowing users to derive values from a normal distribution based on specific probabilities. By understanding its syntax and functionality, you can effectively utilize this function to enhance your data analysis capabilities.