Calculate time

[lachone]

Hello.
I need to know the formula I need to calculate how many days it will take a student to get from the given absenteeism rate down to 10.

• School is 6.5 hours a day
• The numbers are in general format

I thought about putting some other formula (school day formula) that adjusts automatically (like the today formula), only counting Monday - Friday. I haven't been able to figure that out yet.

TODAY FORMULA HERE​	SCHOOL DAY FORMULA HERE ?​
STUDENT​	OCT​	DAYS​	NOV​	DAYS​
YOLANDA	20.88%		22.34%
JAMES	15.06%		12.44%
NICOLE	62.02%		11.06%
ANTHONY	35.73%		27.25%
PARIS	12.2%		25.10%
MICHAEL	11.6%		14.59%
NOA	15.21%		24.01%

 

[Rijnsent]

Hi there, can you elaborate a bit?
So if I look at YOLANDA, she has a 20.88% absentee rate in October and 22.34% in november. In October there were 31 days, but only 23 weekdays. So say you have 23 weekdays with 6.5 hours of lessons, that is 23*6.5=149.5 hours of lessons. With a 10% absentee rate, people can miss maximum of 14.95 hours. And looking at YOLANDA, she probably missed about 34.2 hours. So say you start calculating from October, you are probably looking for a formula where 34.2 equals 10% and than calculates till what date people have to have a 100% show rate to get the absent rate down to 10%?

Is that what do you want to calculate? The number of hours someone missed? Please give some practical examples and desired outcomes, that helps helping you to find the right formula.