confidence interval

  1. H

    Generalisation of 'overlapping confidence intervals'

    I had a question about a common (possibly incorrect) trend in the medical field to look at whether two 95% confidence intervals overlap as a sign of statistical significance at the 95% level. I'm aware this is overly conservative. I've heard that 83% confidence intervals are 'better' but not...
  2. T

    CI from normal distribution using indicator random variables

    Suppose that {X_1,X_2,...,X_n} is a random sample from N(m,1). Let I_i be indicator random variables such that it is 1 if X_i <= 0 and 0 otherwise. Calculate the 95% confidence interval for m. Suppose that sample is large enough.
  3. M

    What is the Confidence interval of this...?

    HI Friends, I've attached excel sheet having 19 records. Can you guys pls help me in finding 95% confidence interval for this. I tried finding it all way, but I'm not getting correct answer. Should t- distribution or Normal distribution be used..? I Thank in advance. Pls help me in finding...
  4. C

    Confidence Interval Problem

    So I have a target with X and Y coordinates. I find the minimum circle indicated by thick green line. I have the center to that circle X,Y. I get the distribution of the bullets from the X,Y position in Radius terms. What I want to do is predict the probabilty of them falling into the 90%, 95%...
  5. O

    Sample size and width of bootstrapped confidence intervals

    Hello all, I am looking for some help on confidence intervals calculated using the residual bootstrapping technique. For confidence intervals calculated according to multipling the t stastistic by the standard error of the mean, there is a clear link between the width of the interval and...
  6. I

    Sample Estimate expression in Brunner-Muenzel test with R (lawstat)

    Dear Talk Stats Community, I try to provide a reasonable interpretation of Sample Estimate expression P(X<Y) + .5*P(X=Y), which is shown as an output for BM-test in R (lawstat package). I am confused with the relationship between the following three probabilities: P(X<Y), P(X>Y), P(X=Y)...
  7. T

    Minimum Accepted Sample Size for Tolerance Interval (confidence interval)

    Hi, I'm using the tolerance interval function in minitab, my sample size is limited to 7 (the parts are expensive blah blah) I've heard to be statistically significant a sample size of 30 is recommended but in practice how low can I go for sample size when using a confidence / tolerance...
  8. H

    Difference-in-differences in Health Economics Research

    Hi, I'm doing a difference-in-differences analysis of a health policy intervention. Health clinics are paid for the percentage of eligible patients who they give the right treatment to. The clinics are measured/paid separately for each type of treatment indicator. One year, some of the...
  9. V

    T-testing of two samples(question about t-statistic)

    Hi have two questions regarding an t-test assignment i did. Basically the null hypothesis was that if sample x2 differed 35 off the mean from sample x1 was it reject-able? The mean of sample x is 395 The mean of sample ý is 435. So the issue is that i think the nominator for the t-statistic...
  10. F

    Constructing intervals VS hypothesis testing?

    Hi folks, let me briefly anticipate that I am a total newby to the magical world of statistics. So, right now I'm preparing for a "quantitative methods for economics" test, but while doing my exercises I found myself wondering about what could be very stupid things. here's the thing: I had...
  11. A

    How can I find an interval estimate for the mean of a Weibull distribution?

    I have a sample of n = 75 taken from a Weibull distribution and have computed mle estimates for the scale a and shape b parameter. The mean of a Weibull distribution (2 parameter) is given as u = a^(-1/b)*gamma(1+ 1/b) In which case I can find an estimate for u by simply plugging in the mle...
  12. S

    Excel 95 % confidence interval

    Hello everybody, I am learning about data science at the moment. I want to calculate the 95% confidence interval for the amount of Long-Term Debt that I could expect to have with Long Term Assets of $50,000,000. I calculated a regression analysis for the impact of long-term assets on long-term...
  13. A

    plot mean value according to confidence interval

    Hi all, i have a very simple question, because i am not good at statistics but i need that :) I have two signals, one is lets say 'x' another is 'time', so its a time serie. I need to find the upper and lower values of my signals according to confidence interval and then show them on a graph...
  14. K

    (A Possible) Pooled P-Test Problem

    Historical data shows that 4% of the components produced at a certain manufacturing facility are defective. A particularly harsh labor dispute has recently been concluded, and management is curious about whether it will result in any change in this figure of 4%. A random sample of 500 items...
  15. K

    A simple confidence problem that I can't seem to solve

    Mr. Grumpy and Mr. Happy are both running for Governor. Mr. Grumpy will eventually win the election with 51 percent of the vote. A day before the election, a state-wide newspaper surveys 100 people about their choice for governor. Assume that survey respondents accurately report who they will...
  16. J

    Confidence Interval in Statistics test

    Hi all, I just had a test with the following question, of which I doubt the 'correct' answer: Taking a level of significance of 5% in a hypothesis test and not rejecting the null hypothesis, is the same as saying: A. We are 95% confident that the results have occurred by chance B. We are 95%...
  17. M

    Nonparametric data analysis

    I'm asking for advice. Topic of my research is brain iron accumulation. My task is the next . I have one dependent variable that is cathegorical and binominal(patient has the pathology or does not). And six independent variables that are continuous and nonpatametric. The question is :how can i...
  18. K

    Formula for the Confidence interval?

    Formula for the Confidence interval, assuming for a Sample whose standard deviation is same as Population. I need to know the exact formula. I need to know if there is any square root of n in the denominator. Anyone who knows the formula please share.
  19. A

    [AMOS] - interpretation of bootstrap indirect effects for one-tailed hypothesis

    Hello all, I'm testing for mediation using bootstrapping in AMOS. This method reports results for two-tailed significance, but my hypotheses are directional. With bootstrapping, significance is assessed based on confidence intervals - though a p-value is also provided. For regression, I would...
  20. A

    AMOS - interpretation of bootstrap indirect effects for one-tailed hypothesis

    Hello all, I'm testing for mediation using bootstrapping in AMOS. This method reports results for two-tailed significance, but my hypotheses are directional. With bootstrapping, significance is assessed based on confidence intervals - though a p-value is also provided. For regression, I would...