1. P

    Skewness and Kurtosis of a t-distribution

    What is the skewness and kurtosis of a t-distribution, as compared to the underlying population distribution? Is it larger, smaller, or is there no definite rule/pattern? Was asked this in an interview and didn't know the answer. Thank you!
  2. S

    F-distribution and T-Distribution

    I have this questions from my test. Can you please help... State True or false 1.The test statistic for the difference of population variance follows an F-distribution 2.The test statistic for the difference of population means, when population variance are unknown, follow a...
  3. H

    multinomial distribution and degrees of freedom

    Hi I have some data from a housing survey (sample size 13,500) and have found that the proportion of privately rented housing is slightly higher than the proportion of social housing. i want to test if the proportions are different. I found some advice at the link below indicating that I must...
  4. N

    Confidence Intervals for r: Why must we standardize?

    Hello! I know we are supposed to convert our r-values to z-values (and standard error) in order to calculate confidence intervals. I am a bit confused why we must do this. The sampling distribution for Pearson's r is a t-distribution and we use a t-crit in confidence intervals when our N...
  5. S

    Finding constant c such that a quantitiy has a t-distribution

    Here is my question, and I am not exactly sure where to start: Question: Let X1, X2, ... , X5 be a random sample from of size n = 5 from N(0, σ^2). Find constant c so that c(X1 - X2)/√(X^2 (3) + X^2 (4) + X^2 (5)) has a t distribution. How many degrees of freedom are associated with this...
  6. J

    Distributions and means - confidence interval question

    Hi folks, :wave: I think I did my research but I would like to be sure before continuing. My task is to find the mean price of a given item in a given country and I need to know how accurate my sample mean is vs. the actual population mean. Here is what I have. (My proposed, probably...
  7. J

    Student's t-distribution table

    Dear all, In a Lineair Single Regression example, I have a hypothesis: H_0: ß = 0. Normally T will than be: T= (b - ß) / se(b) but, since I test wherever ß = 0, i can use: T= b / se(b) Question 1) Is this correct? or is there another reason why i may use T = b / sec(b) ? (in stead...