Use this online percentile mean standard derivation formula to calculate your examination percentile scores and also to solve many different percentile problems.
The percentiles are normally used to compare the scores of your examination. Just know the mean and standard deviation of the data set and substitute in the percentile mean standard deviation formula. The 50th percentile is the mean of the observed data. The 84th percentile can be calculated by adding the mean and standard deviation values. The 97.5th percentile is the sum of mean with twice the standard deviation.
So find what will be yours and your friends percentile scores for all the examinations using this percentile mean standard deviation formula.