1. Y

    Averaging percentiles

    Hello everyone, I am new to this forum and do not have a strong Statistical background. Recently I had to deal with the issue of averaging of percentiles. I noticed that in the transcripts of its students, my school is displaying the percentile in each subject and ultimately the percentile of...
  2. M

    Inverse of CDF

    I am struggling to understand the second formula. I understand the first formula. I don't understand why F(x) is greater than or equal to y in the second formula. Shouldn't the sign be similar to the first formula?
  3. B

    How to find a median of medians? No raw data

  4. A

    25th percentile of right-skewed and left-skewed distribution

    Hi All, Is it possible to have two lists of numbers with the same number of elements and same average, where one has a left-skewed distribution and the other has a right-skewed distribution and the 25h percentile of the numbers with the right-skewed distribution is smaller than the 25th...
  5. K

    Graph: Percentiles and Log Wage Change

    Hello all, I work on a cross sectional data for six years that has log wage information of workers. In order to show how log wage at different percentiles changed from the year 2000 to 2005, I want to make a graph that has 10th,20th,..,90th percentiles on the x-axis and corresponding log...
  6. A

    Collapsing variables

    Hey there, I am new to STATA and would like to solve the following problem: Lets say that I have variable "consumption of cereals" and variable "net income". I would like to find out how much of cereals is consumed in average by the poorest 10% and the richest 10% of the population in my...
  7. M

    [Statistica] Command for percentile / bootstrap

    I am trying to get 0.05percentiles (median 095 CI) out of the bootstrap procedure in Statistica. I found the following command for median of my population: > Use file name > Sample boot(perm number,number of samples)/ median confi = 0.95 > Cstatistics variables Can anyone suggest what...
  8. K

    Bootstrapping with One-way ANOVA design and confidence interval

    Hello, I am new to this forum, and I need some helps in bootstrapping. I am using Matlab. So, here's the study design: I have three groups (Group1, Group2, Group3), 30 subjects/group each. They all have some brain imaging scans (FDG-PET). Within each group, I calculated some parameter...
  9. V

    Is this a correct statement regarding a normal distribution?

    Note: this is not homework. I am trying to make sure I understand the differences between percentiles and z-score. Please tell me if the following compare/contrast statements are correct. Thanks, Mike 1. The 95th percentile is the value such that 95% of all observations are below...