Recent content by GretaGarbo

  1. GretaGarbo

    Excel - Statistics

    When you sample n=40, what is your conflusion about the distribution? Why did they ask you to do this exercise?
  2. GretaGarbo

    Excel - Statistics

    Yes!
  3. GretaGarbo

    Excel - Statistics

    You can call your variables whatever you want, y, t, x, s or anything. So x_bar normally mean the mean of x. jag thought that was obvious, at least for your teacher. :) Now, what have you learnt from this experience?
  4. GretaGarbo

    Excel - Statistics

    y_bar is the mean of a variable y. yes. But the n is 5. you take 5 random numbers and compute the mean. Then you do a histogram of 100 such means.
  5. GretaGarbo

    Excel - Statistics

    You are improving! But you should use this to standardize. z = (y_bar - mu)/(sd/sqrt(n)) Note that the standarddeviation in the MEAN is sd/sqrt(n).
  6. GretaGarbo

    Probably a silly question

    Yes. Yes you can. I have seen the formalism in multiple inference for that yes you can conclude that. (Although I can't remember the formalism now.) And besides, anybody would spontanously conclude that. (And it is certainly not a silly question.)
  7. GretaGarbo

    Excel - Statistics

    In your formula you have = -$B$s3*LN( 1- A15) it should simply be = -2*LN( 1- A15) So you insert “2” as the population mean. (Try some other values like 5 and 9) The mean of many values should be around 2. Create in one row 2 uniformly distributed values. Transform that to 2 exponentially...
  8. GretaGarbo

    Excel - Statistics

    You should: 1) generate 2 exponential distributed random numbers 2) compute the mean of that 3) standardize that 4) repeat the whole thing 1) 2) 3) 100 times and save the standardized mean 5) do the same with 3 exponential distributed random numbers etc Show that you can do step 1)...
  9. GretaGarbo

    Excel - Statistics

    If you want to ask something then you must be clear about what you are asking. (I cant find it.) So rewrite the question. What do you think σx̅ means? It does not mean "standard deviation of the sample".
  10. GretaGarbo

    Help! A question of MLE

    There is no theta in that density. :) Be careful with what you write! (But is it not pretty obvious? What happens if you take the log?)
  11. GretaGarbo

    Excel - Statistics

    When the text talk about "lambda is the rate parameter or 1/mean." then it is teh population mean. Just like your stuff should have a population mean of 2. When the test says "Step 2: Calculate Mean of the Random Numbers", then it is the sample mean. The idea is to consider how the sample...
  12. GretaGarbo

    Excel - Statistics

    I asked if you can generate an exponential random variable. Or can you generate a uniformly distributed random variable? The link you gave said it can be done with the command “RAND()” in excel and it said further how to transform that to the exponential distribution. Try to do that! Read the...
  13. GretaGarbo

    Excel - Statistics

    I repeat this question.
  14. GretaGarbo

    Excel - Statistics

    The idea with this site is that many can contribute – and correct me if I am wrong – and that many can read and learn.
  15. GretaGarbo

    Excel - Statistics

    Note that to get standardized values, when you take the mean of a variable its "spread" will depend on the sample size. So that: z = (y_bar - mu)/(sd/sqrt(n)) You need to divide by the square root of the sample size. (I have no idea how to do this in excel. I do it in R) But can you generate...