Which function would you use to derive the mean of a normal distribution at a specified probability?

The function used to derive the mean of a normal distribution at a specified probability is the NORMINV function. This function finds the value of the variable associated with a specified cumulative probability in a normal distribution. It takes three arguments: the probability for which you want the corresponding value, the mean, and the standard deviation of the distribution.

When you want to know what value corresponds to a certain cumulative probability in a normal distribution, NORMINV provides this capability by inverting the cumulative distribution function. This allows you to determine specific values at which the probabilities occur, which is essential in statistical analysis and decision-making scenarios where determining thresholds or cutoff points is necessary.

In contrast, NORMDIST gives the cumulative distribution function value for a particular x at a specified mean and standard deviation rather than providing the inverse value associated with a probability, while ISNULL checks for null values and RAWVALUE retrieves an unformatted data value. Therefore, NORMINV is the correct choice for obtaining the mean or specific value at a certain probability in a normal distribution context.