Linked Questions

5 votes
2 answers
68k views

t test with drastically different sample sizes [duplicate]

I'm investigating if two of our processes are producing products with the same or different average measurements. The first process has been used for a very long time and thus I have a sample size ...
Omar123456789's user avatar
8 votes
4 answers
6k views

What method is preferred, a bootstrapping test or a nonparametric rank-based test?

I want to perform a single-tail test on a single sample of real numbers (N~100) against an expected value. The population is known to be not normally distributed. So from what I've read about stats, I ...
Paul Lam's user avatar
  • 255
9 votes
2 answers
3k views

Two methods of using bootstraping to test the difference between two sample means

I'd like to bootstrap test a hypothesis (two sample Student's t-test). In Efron and Tibshirani 1993 p.224 there is explicit code for that: for each observation, subtract its group mean and add the ...
Lil'Lobster's user avatar
  • 1,478
4 votes
2 answers
3k views

converting a bootstrap confidence interval into a p-value

If a bootstrap confidence interval (CI) can be interpreted as a standard CI (e.g., the range of null hypothesis values that cannot be rejected) [also stated in this post]. Is it ok to derive a p-value ...
quibble's user avatar
  • 1,694
0 votes
1 answer
2k views

How to test right-skewed distribution hypothesis?

Statistics is new to me. My dataset has 7000 incidents that were processed within x number of days. I took a sample of 400 from the population: ...
coverbook's user avatar
0 votes
1 answer
2k views

R : Calculate a P-value of a random distribution [duplicate]

I want to get the P-value of two randomly distributed observations x and y, for example : ...
Manuel's user avatar
  • 21
1 vote
1 answer
839 views

Very small sample compared to comparatively very large baseline

I would like to know if a small test group (~5 samples) is significantly different from baseline (300-400 samples). I initially considered Student's T-Test, but it seems that I wouldn't be able to ...
kdk's user avatar
  • 43
3 votes
0 answers
99 views

Confidence interval for the ratio

I have a problem that each customer gives us a revenue and a cost, one of the indicators of the company is the: $\frac{\sum Costs}{\sum Revenue}$ To estimate the confidence interval for this parameter ...
Roger Danilo Figlie's user avatar
3 votes
0 answers
91 views

Using non-parametric bootstrap to assess relative difference between means of two samples

Let's say we have 2 samples, A and B. I'd like to find out which distribution has a higher mean by using non-parametric bootstrap. My procedure goes like this: Calculate the mean of a resample 1 from ...
mihagazvoda's user avatar
1 vote
0 answers
126 views

Using bootstrap to compare performance of two machine learning models

I have a binary classification problem, and two ML models $A$ and $B$. I evaluate performance of these models using the area under the ROC curve (AUROC). I want to assess whether model $A$ is ...
Jonathan's user avatar
  • 111
1 vote
0 answers
44 views

Comparing means of a small sample with non-normally distributed data

I am confused about how best to compare means when the sample is small and they are not normally distributed. I have survey data which measured the mental wellness status of a very small sample of a ...
kpm's user avatar
  • 59