The expected urine output for an adult is 0.5ml/kg/hr. This roughly equates to 30-40ml per hour in an average sized adult.
The first step is to compute the rank (R) of the 25th percentile. This is done using the following formula: R = P/100 x (N + 1). where P is the desired percentile (25 in this case) and N is the number of numbers (8 in this case).
Percentile: the value below which a percentage of data falls. 80% of people are shorter than you: That means you are at the 80th percentile. If your height is 1.85m then 1.85m is the 80th percentile height in that group. The data needs to be in order! To calculate percentiles of height the data needs to be in height order (sorted by height). To calculate percentiles of age the data needs to be in age order. And so on. A related idea is Deciles (sounds like decimal and percentile together), which splits the data into 10% groups: The 1st decile is the 10th percentile (the value that divides the data so that 10% is below it)