What is the method for obtaining the integral of a function that represents monthly distribution?

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The method for obtaining the integral of a function that represents monthly distribution depends on the specific function. However, typically, one would integrate the function over the interval of interest, which would give the total amount of distribution over that interval. For example, if the function represents monthly sales revenue and the interval of interest is one year, one would integrate the function from January to December to obtain the total sales revenue for the year.