This statistical function returns the exponential distribution. We can use this function to model the time between events, such as how long an automated bank teller takes to deliver cash. Syntax: EXPONDIST(x,lambda,cumulative) x is the value of the function. lambda is the parameter value. cumulative is the logical value that indicates which form of exponential function to provide. If this value is "true" it returns cumulative distribution function, if "false" returns probability distribution function.