Syntax. NORM.S.DIST(z,cumulative)
Definition. This function returns the values or probabilities of the distribution function of a standard normal distributed random variable. The standard normal distribution has a mean of 0 and a standard deviation of 1. Use this function instead of a table containing the values of the distribution function of a standard normal distribution.
Arguments
z (required). The distribution value (quantile) for which you want to calculate the probability
cumulative (required). The logical value that represents the type of the function. If cumulative is TRUE, the NORM.S.DIST() function returns the value of the distribution function (cumulative density function). If cumulative is FALSE, the NORM.S.DIST() function returns the value of the density function.
Background. The NORM.S.DIST() function returns the probabilities of a standard normal distributed random variable. The standard normal distribution is a normal distribution with the arithmetic mean μ = 0 and the standard deviation ó = 1. The equation for the density function of the standard normal distribution is:
See Also
You will find more information about normal distributions in the descriptions of NORM.DIST() and STANDARDIZE().
Example. To explain the example of the NORM.S.DIST() function, we will use the same example as for the STANDARDIZE() function. You are a light bulb manufacturer and want to analyze the performance of light bulbs. You have already entered the measurements in an Excel table. You also calculated the average life cycle and the associated standard deviation. You calculated the standard distribution values with the STANDARDIZE() function.
Now you want to use the NORM.S.DIST() function to calculate the values or probabilities of all standard normal distributed variables of the distribution. What arguments does this function require?
z = the distribution value (quantile) for which you want to calculate the probability. In this case, this is the performance in the form of the standard normal distributed z-value.
cumulative = the logical value that represents the type of the function.
Figure 12-106 shows the results.
You can make the following statement from the results: The probability for the standard normal distributed value –1.728 (cell D2) is 4.2 percent (cell E2).