Setting Numerical Limits in a Cell

[Raiderman]

How would I set a numerical limit in a cell? Example like only being able to enter in a number between 1 and 100, if someone did no enter a number fitting this criteria then the cell would not allow it or just be blank.
Also when how would I figure out how to find out the average of 7 cells but only six of the cells have data.. In this instance I would only want the average of the 6 cells that had data not the original 7 cells. Any help would be greatly appreciated.

[mewingkitty]

First answer -
Go to data validation on your data tab. Choose either decimal or whole number. Then enter your min and max acceptable entries

Second answer -

=SUM(D1:D9)/COUNTA(D1:D9)

Something like that will sum the cells, then divide them by the # of cells which contain data, disregarding blanks.

mew!

[daddylonglegs]

Average function ignores blanks so if your "blank" cells are truly blank, i.e. not zero, then you can just use a regular average,

=AVERAGE(A1:A7)