1. J

    Sampling to find uniques in population

    The problem I am facing is: Imagine I have a bag of N marbles, where the value of N is known. In the bag there are k different color marbles. Our goal is to estimate the value of k. I take a sample of size n. The question is, how can I use this sample data to estimate the value of k?
  2. C

    Combining missing information of duplicate cases

    Hi I have a problem with a very large dataset (containing more than 20000 cases and about 350 variables). This dataset contains many duplicate cases of which in some rows some information is missing. What I need to do is to join information from duplicate rows with the same unique identifier...
  3. L

    Need help frequencies within variable combinations

    Sorry if the title is not the best description. I'm mentally exhausted from the last 10hrs. I have 1500 title entries. Half of them are duplicates. It was nominal string and I recoded as numeric for testing. My main category variable is also nominal. Each case within a set of duplicates is...