please can any one help me to do this calculation with IF function

[mazan2010]

Dear sir
would you please someone help me to do this with excel
the case as the follow

suppose i have 5 value as the following
cell A cell B Cell C Cell D Cell E
100 88 62 34 10
my equation is

(value > 50 - 50)/(Value >50 -Value <50)
my manual calculation which i do as the follow

(62-50)/(62-34)=0.428
i need to do this with excel which automatically do this
Note (from my example you can see i take the value 62 and 34 not take 88 or 100 or 10 because i need the nearest value to 50 which fail in between (34 , and 62)
i hope you understand me
Regards

[benishiryo]

welcome to the forum, mazan. are they always sorted in descending order? if so:
=(LOOKUP(2,1/(A1:E1>50),A1:E1)-50)/(LOOKUP(2,1/(A1:E1>50),A1:E1)-INDEX(A1:E1,MATCH(TRUE,INDEX(A1:E1<50,),0)))

if not:
=(SUMPRODUCT(MIN(1E+100*(A1:E1<=50)+A1:E1))-50)/(SUMPRODUCT(MIN(1E+100*(A1:E1<=50)+A1:E1))-SUMPRODUCT(MAX((A1:E1<50)*A1:E1)))

if it doesn't work for you, I suggest you upload an Excel file in the thread with more examples. To do that, Click on GO ADVANCED and use the paperclip icon to open the upload window.
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[mazan2010]

really thankssssssssssss Dear for quick response

[mazan2010]

Dear benishiryo
if i have this example
Cell A Cell I
100000 100
10000 88.88888889
2000 53.33333333
400 16.66666667
80 4
i need to select automatically value corresponding to more than 50% from column A
in this example is 2000 then take log and subtract from your function you made
hope u understand me