Currently I have data (true population size is unknown).
There are n
data points in descending order, and we know the values of 25%
and 50%
percentile, say x1
and x2
. How can I estimate if the sample size is sufficient such that x1, x2 are within 5% of margin of errors
of x1
and x2
?
For example, suppose n=1000
and data={4500, 621, 500,....0.001}
, and the 250-th, 500-th observations are x1=200
and x2=50
. How can I know if n=1000
is big enough such that even if increasing n
, x1=200 +/- 10
and x2=50 +/- 2.5
?