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  1. hlsmith

    Interpretation of logistic regression results

    Well you also have your intercept, which would be when both predictors are set to zero, then purchage type when custom set to zero, vice versa, and then the when both set to 1. It is all about making sure you know which variable group is set as the reference, we can't tell from your post. Can...
  2. hlsmith

    Comparing group means with drastically different sample sizes

    What program do you think you will be using? I just grabbed this image off the internet, but this is what you would expect as the output: You sent them up similar to a regression and get output like this for each variable. So the y-axis is for the outcome and the x-axis is the comparison of...
  3. hlsmith

    Compare regression coefficients

    I would look at the partial R-squared values in a multiple regression. So regress true height on X1 and X2 and calculate the partial R-square values with confidence intervals. This isn't a direct comparison between them, but it will quantify the amount of variability in Y explained by each...
  4. hlsmith

    regression issues

    You need to think about the relationships between the variables. If it is exogenous, it won't be a big deal. If it is a mediator, you just won't know its effect but its cause should help explain the outcome. It all depends on the purpose. If you are using ORs, RRs, or RDs as your outcome...
  5. hlsmith

    regression issues

    I have told you this before, run the model with and without the extreme outliers, if it doesn't substantially influence the estimates you are fine.
  6. hlsmith

    Why depend on numbers?

  7. hlsmith

    Duel Links Card Pull Probability

    Cold people are not the only ones that shake.
  8. hlsmith

    Post hoc power analysis

    I wouldn't call it post hoc, since you haven't ran the study analyses yet. Post hoc power analyses are a major faux pas, since most people do them after finding significant results.
  9. hlsmith

    Using racial distribution for a population data as a reference

    No problem. Welcome to the forum!
  10. hlsmith

    Using racial distribution for a population data as a reference

    If you are just desiring to report on historic data and are not generalizing or predicting, then you are correct. So your conclusions will be your conclusions. Though you can still use stats (means, correlations, rates), you just don't have to add precision values (confidence intervals or...
  11. hlsmith

    Using racial distribution for a population data as a reference

    Please better describe this, it currently isn't clear what you plan to do. Also, since this is time to event data, a proportional hazards model may be more appropriate.
  12. hlsmith

    COVID Probability

    T cells, yes. I'll update duration next week, but someone could have 95% lower antibody response hypothetically, though what is the true threshold for not being able to combat exposure. UNKNOWN.
  13. hlsmith

    COVID Probability

    Aerosalized transmission is the treat. Idiots at my gym have never worn masks. I have been fully vaccinated for months and always wear my mask, part of the 3% that do. Though these idiots all of a sudden wipe the machines down, which wouldNt be such an issue if you wore a mask and balked...
  14. hlsmith

    COVID Probability

    Next Tuesday I will start modeling the antibody data I have. I believe starting around three months after infection people dip below the positive threshold which was established awhile back and never really tested on infected patients months out. So you are still making the antibodies (IgGs)...
  15. hlsmith

    COVID Probability

    The VE part would be too difficult to incorporate, since variants are now prevalent, we don't know the actions of people in the studies (beyond assumed being typical), and the community exposures would have been different for them. What would need to be known is some type of almost lab data...
  16. hlsmith

    perfect collinearity.

    SAS knows composite combinations, look in the log to double check. Why do it with 71 vars when you could do it with say gender?
  17. hlsmith

    standardizing variables

    Gelman has one "l" in his name.
  18. hlsmith

    COVID Probability

    There are an insane amount of assumptions to be made here... (34,000/39,510,000) + (33,999/39,509,999) +,..., (33,990/39,509,990), for probability of an interaction w/ an infected person. probability of transmission based on data from trial 90% = 1 - 0.1 = (5/1000) / (50/1000), it is a...
  19. hlsmith

    Stupid post for a newbie. There is a premade table. How do I know which gender is which number?

    No idea, but can you surmise it by looking at the other variables, like income, age, etc.?
  20. hlsmith

    Evaluation of statistical data.

    B seems alright. D, I would phrase it in regards to your sample of existing murders, not if you were to get murdered, as mentioned, things change, your sampling may be off, you didn't control for particulars, and who is you (Americans? from blank to blank, etc.). Welcome to the forum.