Understanding Gate Score calculations

Question

I am trying to understand the calculations behind the gate rank so that to get a feel of how our actual marks,ranks and gate score is mapped.

Scorecard mentions the formulae used to be 

Gate Score = Sq + (St - Sq) *{ ( M - Mq )/ ( Mt - Mq ) }

where
M = marks of candidate
Mq = qualifying marks (25 or (μ+σ), where μ,σ are mean and standard deviation respv.,whichever larger)
Sq = Gate Score(GS) corres. to qualifying marks (Mq)  in our exam mentioned on scorecard as 350
Mt = mean of marks of 0.1% i.e mean of top 107 people (as 1,07,893 students appeared) or mean of top 10 (larger of these)
St = GS corres. to Mt and for 2018 exam it is 900

i am using M = 58.33, St = 900, Sq = 350  and GS = 747 
now to estimate Mt by using the rank prediction app (accuracy is 90-95%) we see that top 10 ranks score b/w 76-83 and mean around 79 which is evidently more than mean of 0.1%(top 107) which would be somewhere around 70 so Mt = 79 
if we let Mq = 25 and try to estimate Mt we get around 71 so why this discrepency ?
and if we let Mq be (μ+σ), and solve for Mq using Mt=79 we get Mq=10 which is contradiction as per definition of Mq
Can someone help me resolve this ?



 

Answer 1

Going through your calculations, I think the only possible flaw could be in your interpretation of the definition of Mt which is Mt = mean of marks of 0.1% i.e mean of top 107 people (as 1,07,893 students appeared) or mean of top 10 (larger of these)

I think it means not larger of the means but mean marks of larger of(10 and 107) which will be mean marks of top 107 which could be around 71-72.

I am not sure though.

Comments

You are correct. And this value was shown in Praggy App too.

---

Yes right i misunderstood
Thanks for clarifying