Recently, I was thinking about the calculation of the average value of fixed working capital... And came up with a this formula: where: Фо - cost of basic production means early in the year; Фвв, Фвд - cost of input and outgoing fixed means (Correspondingly); tр, tнр - number of months during which the basic production means "worked" and "not worked". The letters here are conditional. Write those what invented it. What do you think about this formula. This formula is correct?