Hello,
I have a question about getting value of of quartile.
Basically, I always memorize that first quartile’s position is (n+1)/4 (also checked with Google), but with Greg’s way to find value of quartile, the answers are different.
Supposed the data set is 1,2,3,4,5,6,7,8,9,10
With Greg’s solution Q1 would be 3 which is the half way of half.
However, if used the stat formula (10+1)/4 would be 2.75th which would yield 2.75 as the first quartile.
I am wondering why this happens and what should I answer on the test.
Best,
SS
The problem is that the size of the dataset n is not divisible by 4 - the GRE doesn’t tend to deal with that due to the ambiguity you’ve shown.