determining variance in percentages

[emaypsu]

John was in school for 23 out of 30 days last month, which means he was in
school 76.66% of the days. We expected him to be in school for 28 days, or
93.33% of the days. How do I calculate the variance in the percentages?

 

[Mike H]

Try this

=(A2/B2)/(C2/B2)
Format as %

Where

A2= actual attendance - 23
B2= Max attendance - 30
C2= optimum attandance - 28



Mike

 

[emaypsu]

How about this scenario?

attended 23 days out of expected 30, for 76%
projected 25 days out of expected 28 for 89%

does your formula differ?

 

[Mike H]

Hi,

No it doesnt. I have to confess I don't understand the reasoning that gives
100% attendance score if attendance is only 28 out of 30 days but that's your
logic not mine.

Mike

 

[emaypsu]

Thanks. I was using this scenario to apply it to what I was actually
calculating. I appreciate your help.