samples

  1. P

    Which Statistical Test To use?

    HI, I'm struggling to find out which statistical test is most appropriate to analyze the impact of negative interest rates on profitability; Data collected: Sample - 30 Banks Yearly data for each variable from year end 2007 to year end 2017 - 10 years Variables I'm considering are...
  2. C

    What is the population parameter of interest? When the responses are normal?

    The problems said: Students in Stanford are supposed to spend on average 3 hours of time per week for every credit hour they take. Last year, 263 randomly selected seniors were contacted and asked how much total time they spent on their studies over the last week and how many credit hours...
  3. P

    Comparing data from multiple samples - which model?

    Hello My job is to measure electrical characteristics of transistors e.g. onset voltage or threshold voltage. Every wafer I test has roughly 4000 transistors, and I measure many characteristics for each. I perform weekly experiments where I change a variable. I want to know if variable...
  4. H

    Need help: Can i genaralize to the population, or do i have to weight my data?

    I have a sample of 194 households from 3 villages. The number of hh from each village is 61, 67 and 66. I used a 90% confidence level and 10% margin of error to determine sample sizes. (total household population for all three villages is 4194 households). The total sample size for all three...
  5. H

    A uniform distribution problem

    A person's score in a test is uniformly distributed over [0,100]. She is permitted three attempts at the test. However, after the first attempt, she is permitted to either accept that score as the final score or else to discard the score and take the second attempt. Similarly after the second...
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    Sample Categorization?

    Hello, I was wondering if you any of you knew what the best method would be for dividing a large sample (approx 30000) into 'categories'. This is because I will need to further process the data into a model which is very slow (about a sample an hour) therefore if I cut the number of samples...
  7. N

    Sample size for checking that records, known to be in error, are now corrected.

    The Problem I have audited 1000 records and found 100 records to be non-compliant. I have asked for the 100 non-compliant records to be corrected. The individual responsible has responded and said all 100 of the records have now been corrected. What sample size of records do I need to...
  8. N

    Variance and sample error in paired sampling

    Hi everyone, I have a question regarding variance and sample error in paired sampling. If I want to see how a parameter changes over time i take sample "A", then re-sample "A2" at a later time. In my case, the sampling is destructive, so sample A cannot be re-taken at a later time. I will...
  9. I

    How to find sample variance given population mean and variance (no specific data)

    Hi, I am working on the following problem:confused:: Population Mean = 1000 Population Std. Dev. = 400 Sample N=25 How many, from the sample of 25, are greater than 1000 if the sample mean is 1100. Can I assume the sample std. dev. is the same as the population? Does anyone know...
  10. C

    large samples and resampling stats

    First post here. Mods- please move thread if in wrong place. I am working with a very large dataset (total n = 30,000+) of normally distributed measurement data on birds. Sample sizes are such that any and all traditional (e.g., ANOVA) hypothesis tests are statistically significant. Rather...