The NORM.S.INV function in Google Sheets is a statistical function used to determine the inverse of the standard normal cumulative distribution. It is particularly useful for calculating the z-score corresponding to a given probability, thereby aiding in various statistical analyses and decision-making processes.

Syntax

NORM.S.INV(probability)

• probability: A value between 0 and 1 representing the probability for which you want to find the corresponding z-score.

Example #1

NORM.S.INV(0.95)

In this case, the function computes the z-score such that 95% of the data falls below this value. The result would be approximately 1.645.

Example #2

NORM.S.INV(0.5)

Here, the function returns the z-score at the midpoint of the standard normal distribution. The result will be 0, as half the data lies below this point.

Example #3

NORM.S.INV(0.01)

This function call calculates the z-score that corresponds to the lowest 1% of a standard normal distribution. The result would be approximately -2.326.

Error handling

• NUM!: This error occurs when the probability is less than 0 or greater than 1, indicating an invalid input.
• VALUE!: This error appears if the argument given is not a valid numeric value, making it impossible to compute the z-score.

Conclusion

The NORM.S.INV function is an essential tool for analysts and statisticians when working with probabilities in a standard normal distribution. By understanding its syntax and functionality, users can effectively apply this function to various analytical tasks, enhancing their data interpretation skills.