1. sepinaz

    Can we model the experiments as a stochastic process and estimate the sample size?

    I have an image with the size `5575x9440` and I'm implementing a modified version of the algorithm used in this paper on it, but because the code performance is low right now, I have divided the image to `52628` submatrices of the size `25x40 (1000 pixels)` and my first experiments show that...
  2. T

    Power analysis for sample size that measures heterogeneity

    Hi I hope someone can help me with this question here. I would like to do a power analysis for sample size, but I am unsure how to approach it because I am measuring heterogeneity in my dataset. Here are the details: I have two different types of cell lines and I am measuring the growth of...
  3. A

    Choice of Sample Size for Testing Means

    Here they've made a mistake of using Zα/2 since that will be for a two sided test. This particular question is a one sided test so Zα should have been used. Also they multiplied the population variance by 2. Now, my question is how did they calculate that symbol in the denominator. The symbol...
  4. A

    Sample Size for expensive tests

    How do we calculate sample size? Some homosapiens have poked and grunted an assertion of approximately thirty, without giving reason. That is insufficient justification to present to a board for approval of expensive trials. How then do we measure and assess the merits of sample size? For a...
  5. A

    Choice of sample size for testing means

    Is there a reason why this person altered the original formula by multiplying the population variance by 2?
  6. C

    Sample size needed to create bell curve

    Hello again, My boss has looked at my assessment data for my class of thirty children and is querying the accuracy of my data, because my data, when she plots it on a graph, doesn't form a bell curve, unlike the data submitted by my colleagues. I'd like to argue the point that such a...
  7. R

    minimum required sample size

    Can I use the following formula in Excel to calculate the required sample size for some A/B testing for various differing groups? a = Base lines response rate b = uplift in base line response rate minimum required sample size = 26*POWER(SQRT(a*(1-a))/(a*b),2) source...
  8. T

    Does changing our expected results change what our sample size should be?

    I had this question from a school assignment, and my thinking is no that what we expect does not change what our sample size would be. I know a larger sample size is best, but , For example 1. If we have a Fair 3 sided dice and expect 1, 2, or 3 to have equal probability of coming out, and we...
  9. X

    set of pairwise non-commuting elements with maximal size

    Let G be a finite non-abelian group. Let [G:C_G(g)]=2, for all g\in G\setminus Z(G). Let x\in G\setminus Z(G) then we have G=C_G(x)\cup C_G(x)y, for somey\in G\setminus C_G(x). It is easy to see that xy\notin C_G(x)\cup C_G(y). Now how can we show that the set {x,y,xy} is a pairwise...
  10. D

    Chi square test sample size

    Hello, Does sample size affect the chi square value and Cramer's V? Can someone explain? Thank you!
  11. D

    Effect size

    Dear MHF, I was just wondering if you could help me understand how to calculate the effect size of a data set. I am having difficulty with the data set I am using (see attached file) and I would like to know if it is possible to calculate the effect size of this data set. Your help is much...
  12. M

    company by revenue and fleet size

    Patriots vs Colts Live Streaming
  13. H

    Find the Sample Size

    Roll two fair dice. Each die has six faces. • Let A be the event that either a 3 or 4 is rolled first, followed by an even number. • Let B be the event that the sum of the two rolls is at most 7. The sample size i got is A = [ (3,2), (3,4), (3,6) (4,2) (4,4)...
  14. T

    Finding sample size

    Xn and Yn are random samples with means μx and μy and normal variances (sigma squared sub x,y not sure how to access symbols) and are normally distributed. Suppose the variance of x = 2 and the variance of y = 2.5 and that the sample sizes m=n. Find sample sizes so that (Xbar-YBar) will be...
  15. A

    z test: How does sample size affect type I error?

    I need help with the following: Suppose we have a population, and a sample X of size n from that population. I need to determine which of the underlined option is true, in each statement: 1. When the size of the sample n grows, if the null hypothesis H_0 is wrong, then the probability of...
  16. F

    In triangle, 1 angle is twice as big as 1 angle and 3/4 the size of the other. Help!

    In a triangle (180 degrees), one angle is twice as big as one angle and 3/4 the size of the other. What is the measure of the smallest angle? How would you solve this? I have tried working backwards (as in, from the answers) but to no avail. There are too many variables? Choices: 48 96 98 72...
  17. D

    getting the no of sample size needed to obtain the signifance level

    in this question , i am asked to find the smallest successful cases needed to obtain the 5% level of significance... the sample size is small (only 20 for this question) ... But how if the sample size is big? certainly , i cant find it by trial and error one by one... Can someone taech me the...
  18. S

    Proving sum of inclusion probabilities equals sample size n

    I am having trouble figuring out where to get started in this proof.Let πi be the inclusion probability of unit i in some sample scheme for drawing n units out of a population of size NHow can I go about showing that the sum of all πi for i from 1 to N is equal to the sample size n?Any help...
  19. T

    Sample size

    The question is: You want to estimate the percentage of US statistics students who get grades of B or higher. How many such students must you survey if you want 97% confidence that the sample percentage is off by no more than two percentage points? Could someone explain to me how to handle...
  20. L

    How to Calculate the Mean Effect size concerning a meta- analyses of five studies.

    How do you calculate the mean effect size for thesestudies. Use Cohen’s conventions to describe the mean effect size youcalculated. d= 0.67 d = 0.03 d = 0.32 d = 0.59 d= 0.22