Search results

  1. Dason

    Why is the result of my t-test shows texts in red?

    What software are you using
  2. Dason

    t vs Z, distributions and testing

    If the reader will answer my question then I'll consider it.
  3. Dason

    t vs Z, distributions and testing

    I'm not trying to be a jerk but you aren't very good at articulating your reasoning and frankly you make a lot of incorrect assertions. Add to that that in almost all of your threads it's very difficult to understand what your goal/motivation is. So yeah I'm just wondering what kind of...
  4. Dason

    t vs Z, distributions and testing

    What exactly is your math/stat background?
  5. Dason

    t vs Z, distributions and testing

    How could you ever possibly believe that sigma/s is a constant when s is a random variable that changes from sample to sample. Maybe it's just a case of you not explaining yourself correctly but being able to adequately articulate your reasoning is vital. But I would suggest reading some...
  6. Dason

    t vs Z, distributions and testing

    I mean... That's wrong. Do you somehow think s is constant? The issue is that it's a random variable. It will change with every sample.
  7. Dason

    t test Type II error %

    Yeah and we told you. You look at the distribution of the test statistic under the specified parameters. But like we mentioned - the t statistic in that situation follows a non central T distribution. I literally don't care about any of the other distribution stuff you post because it isn't...
  8. Dason

    t test Type II error %

    I still don't get your entire approach. Why are you doing all of this when the only question that matters is what distribution does the t statistic have when the alternative hypothesis is true.
  9. Dason

    t test Type II error %

    That is incorrect. I didn't read through everything but if you're using that assumption then your analysis is wrong.
  10. Dason

    t test Type II error %

    I refuse to talk about this anymore until you show how you would do a test for some actual data.
  11. Dason

    t test Type II error %

    Maybe it might help if I illustrate *why* it's not just a shift. First let's start by looking at the test statistic: t = (xbar1 - xbar2)/(Sp*sqrt(1/n1 + 1/n2)) hopefully the terminology is clear enough here. I'm going to make a slight simplification and just define SE = (Sp*sqrt(1/n1 +...
  12. Dason

    t test Type II error %

    So as had been said before it's perfectly possible to do the power calculation. It requires the non-central T distribution to do so. No amount of 'shifting' the T distribution will be able to match the non-central T exactly so you're fighting a losing battle by taking this approach. Your...
  13. Dason

    Normal distribution - online advertising

    I use the Pee table. My kids think it's hilarious. /s
  14. Dason

    Non-linear diagnostics

    I don't necessarily see anything to suggest non linearity. What do the partial residual plots look like if you log transform the dependent variable though.
  15. Dason

    Probability of two players

    Look up "convolution". But yeah the info you gave isn't nearly enough for a discrete random variable and even less so for a continuous one. Just a suggestion for the future - give all relevant details. We have 9 posts here before we even got an outline of what you are actually trying to do. We...
  16. Dason

    Probability of two players

    Ok but still... Not enough info. I mean it's entirely possible for player A to have less than 20 points and player B to have more than 10 in a way that they sum to over 30. So we don't have enough info. Is this literally the only info you have?
  17. Dason

    Probability of two players

    Well the issue is we literally have other points we know must exist but we don't have information to tell us if any of the other point combinations sum to 30.
  18. Dason

    Probability of two players

    I think we would need more info. Are there scores independent. What are the probabilities of any other score they could get.
  19. Dason

    Normal Distribution Help Please.

    That's not nearly enough information to make a decision on whether the data is normal or not.
  20. Dason

    Different coefficients from regression and trendline equation

    I mean I agree. But it's not as bad as it used to be. Did you ever think you'd think we me say that?