At 19:20 10/03/2015 +1300, David Love wrote:
I have a three column spreadsheet.
Column A. Date - The dates are consecutive
Column B. Production - The Production has a daily target of 10,000 units
and each production period is of seven days.
Column C. a formula every seventh cell.
Is it possible to construct a formula which will show in the seventh
cell of column C the average for the number of days of production i.e. if
day 1 reaches a production of 10,000 units I want this figure entered into
the seventh cell in column C.
Hold on! How do you know this is going to be the average for the week? Do
your workers celebrate reaching the daily target and take the rest of the
week off? Surely they need to attempt the same daily target on each of the
next six days? Or do you mean that 10000 is the *weekly* target? If so,
what happens when it is reached? Does production automatically stop to
prevent its being exceeded? Or could some weeks exceed 10000 - even by
If days 1+2+3+4 total, say, 42,500 I want the seventh cell in column C
to show the average of 10,265. In other words I want the average shown for
the actual days of production each seven day period.
So 10000 isn't a weekly limit. In that case, what is the significance of
the 10000? If four days exceed 10000, as here, it's not a daily limit
either: at least one of these days must have exceeded 10000. I'm beginning
to suspect that it has no significance for the calculation (so you didn't
need to tell us): it may be of interest only to the workers' supervisor in
interpreting the results.
You can find the average of non-negative values (i.e. non-zero values in
your case, assuming production cannot be negative) by putting in, say, C7:
If you copy this and paste it into every seventh row of column C, you
will have what you need.
But that leaves you with the rather messy requirement to paste separately
into every seventh row - a process very prone to error. Instead, in C7 try:
ROW() returns the current row number. The MOD() function returns the
remainder on dividing by 7. If this is zero - as it will be for row 7 and
every seventh row thereafter - the required average is shown; otherwise the
null string ensures that there is no display in the cell. You can copy or
fill this down column C without the same risk of error as the previous
suggestion. Note that comparing the result of the MOD() function with zero
will show results in rows 7, 14, 21, and so on. You will have to change the
"0" to "1" to show results instead in rows 8, 15, 22, and so on - and
similarly for other possibilities. Once you have found the appropriate
value, you can fill the formula containing it down the column.
Is it possible for there to be no production at all in a particular week?
The above formula, in evaluating the average of no values, attempts to
divide by zero and displays #DIV/0! . You could test for this and avoid it
in various ways. If days with no production have empty cells in column B,
would suffice. If they have (or may have) explicit zero values, try:
I trust this helps.