Averaging Account Sales. By H. D. GRANT. The most trying part of the work of a bookkeeper for a commission house is averaging the account sales for the current month; and having had practical experience in that capacity, I should like to present a few suggestions. This method is a unit calculation only and has been approved by competent judges as an accurate and simple form of averages to cover large sales. Take, for instance, the sales for a month in a large woolen commission house, which may aggregate $200,000 made up of 2,000 invoices or more, with terms of sale ranging from ten days to seven months and incidental dating covering a number of days. The formula which I submit provides columns to cover such running time, with a supplemental division for uneven days. This unit method is a safeguard against getting the wrong number of days. The old system which is ordinarily used is to abstract the amount of each charge at its due date, from the sketch of sales at the end of the month and multiply each amount, by the number of days intervening between the due date and the focal date or the first day of the month; then divide by the total sales for the month. The method takes two men about two days to figure sales, whereas the unit system takes one man four hours to complete the same number of sales. The columnar arrangement of Form A gives a place for 10 days, 30 days, 60 days, 90 days, 4 months, 6 months, and 7 months with the dates i to 30 on each side. There is a daily sales margin in which may be inserted each day's total sales (in dollars only, no cents being considered). The total for the month is reconciled to the sketch and the first unit of dollars omitted from the total. This total, divided by 3 (which is the same as the original amount divided by 30), will give one day's interest on the total sales. As a sketch clerk enters, say, an item termed ten days June ist, billed on February 5, amount $211 (see sheet entry under February 5), that is, 123 days running time, he assigns it to the columns headed 10 days, 90 days, and to the supplementary division under 23. By footing each column you get the running time at the rate of i per cent. per month; the supplemental amounts are all carried up alongside the daily sales, opposite the running time specified on the actual sale. They are added and carried to the right of daily sales. This amount is multiplied by the running time, which begins with the unit 1, inserted after the first date or on the ad of the month. The result of the extreme right-hand column is the interest on the running time, on the daily sales and the supplemental division, and you get that by multiplying each amount by the unit running time and dividing the total by three. The first unit of the total is omitted, which, as before stated, is the same thing as keeping the total intact and dividing by 30. For example, take 3727. To get i per cent. for 9 days we multiply 3727 x 9 • 30. In the breaks 10 to 19 we add the amounts and affix a cipher; in the breaks 20 to 29 we add the amounts x 2 and affix a cipher. In other words, we do not multiply 2599 by 23 but by 3 and the 20 is taken care of in the breaks. The total interest earned 695.48 is the same as if we took each amount opposite i to 27 and extended these amounts separately, viz. 1 X 1387 + 2 X 5344 + 4 X 2223, and divided each quotient by 30. We then total the interest earning column and divide it by one day's interest on the sales which is, $31.87. This divided into $3,189.30 equals 100; now 100 days from February Ist gives the due date May 12, 1907. The negative to sales, namely, returns and allowances, cannot be covered by this form. The sales begin always on the first of the current month, while the returns sometimes cover a period of six months before and after the date of the account current rendered. This requires a laying out of all the amounts at their due date, before one can find the focal or beginning date. The formula for averaging the credit is illustrated in Form B. The allowances number thousands of small amounts, representing all sorts of dates, and are taken as at the end of the current month in aggregate. The thirty-one perpendicular lines are crossed with horizontal lines to provide a laying out space for the amount of returns. The focal date is the first date on the first laying out space, the numbers 1 to 31 at the top being the monthly date. We get the even month's interest earning at i per cent., by cross-adding each monthly laying out space, which is designated by its title at the extreme left of sheet. The time between the MONTHLY AVERAGE. 10 Days 30 Days 60 Days 90 Days 4 Months 6 Months 7 Months Daily Sales Feb., 1907 3 II 400 2,213 1,619 2 ,213 5.783 5.783 4,291 36 2: 9 136 136 7.085 8.892 5.783 2,021 7.797 2,676 18 956 20 3,867 786 I ,127 839 956 786 647 2II 2,084 2,731 I21 5,179 2,388 752 23 21 |