Hypothesis testing assesses whether data support a given hypothesis rather than being an effect of random fluctuations or some other process described by an alternative hypothesis.

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20 views

Testing the equality of two proportions [on hold]

An undergraduate research project involves a beetle that lays an egg on a bean. After several days, a new adult beetle chews its way out of the bean. Sometimes, it does not work and no adult beetle ...
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39 views

How to name the concept of the mean shift divided by the standard deviation

In the context of a paper dealing with Statistical Quality Control, I am defining and using the concept of the mean shift divided by the standard deviation of a (normally distributed one-dimensional) ...
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0answers
23 views

How to check $H_0$ hypothesis using Pearson's criteria?

How to check hypothesis by using Pearson's criteria, that $H_0:$ random variable $X$ is normally distributed given that $k=7$ (count of intervals) and $\alpha=0.1 $ (significance level). I do ...
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15 views

Likert Scale , SPSS and hypothesis

We made an online research that aimed to see if "have a pet" could influence "good perception about self". 69 participants answered 21 direct questions with this likert points (5.totally agree, ...
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30 views

Comparison and testing multinomial coefficients

Straight to the problem I want to test the hypothesis that two coefficients of multinomial regression model are equal between them. For example, considering a model where Y is 3 level categorical ...
1
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1answer
23 views

Is there a way to evaluate observations of exponentially-distributed variables, where some of the observations are still “alive”?

I am looking at the tenure (i.e. elapsed time between hire date and termination date) of various employees in a system. I want to test the hypothesis that two groups of employees have the same tenure ...
7
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2answers
73 views

How should I model interactions between explanatory variables when one of them may have quadratic and cubic terms?

I'm sincerely hoping that I have phrased this question in such a way that it can be definitively answered--if not, please let me know and I will try again! I should also I guess note that I will be ...
3
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1answer
10 views

Test autocorrelation in irregularly(unevenly) spaced time series

I have a dataset that includes observations at different time points. There are multiple observations at the same time points and the time points are not evenly spaced. Now, I would like to test ...
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1answer
44 views

How to test an extra small sample is from discrete distribution?

My sample size is less than 7. The discrete distribution has 5 values, skewed, bell-shaped. How to test that the sample is from this distribution?
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1answer
41 views

Proportions Test for when one sample has lots of zeros

I tried using chi-squared test, but it is giving me odd results, For example: Let's say that I am testing whether behavior between male and female users is the same. Males only bought 3 units of ...
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3answers
46 views
-1
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0answers
29 views

False rejection rate of simulated values in R [on hold]

I need to create a table of Estimated Rate of False Rejection of Null Hypothesis in testing at the Nominal $0.05$ level for selected $n$ and $k$ in simulating values from the Gamma Distribution with ...
4
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0answers
21 views

Testing for statistical differences of quantile regression line slopes

If I were to compare the statistical similarity between the slopes of OLS regression lines from two independent samples, I would use a t-test to test if the slopes are equal or not. I'd like to ...
4
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2answers
36 views

Population is normal with known variance and mean. Sample size is small. Which case?

Given a population (normal distribution) mean and variance and a sample set with n<30 values, how should I perform hypothesis testing. My professor told me that I should be using the t-test for ...
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0answers
14 views

Why is there under-rejection using the distribution of a bound?

In Hansen(1992), the author derives a bound for the likelihood ratio statistic and the limiting distribution for this bound: I'll simplify the notation and the reasoning, while maintaining it's ...
2
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0answers
13 views

Testing semi-parametric versus parametric model

I am estimating a (semi)parametric and a parametric model for a panel data set, and I want to test the functional form by applying the method proposed by Henderson et al. (2008, p.267). In particular, ...
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0answers
8 views

Joint significance testing w/ large samples

long time listener, first time caller. Unfortunately I can't show code as the computer the analysis is done on has rather tight security. I need to test for joint significance in a logit model that ...
3
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1answer
160 views

independent replicate experiments yielding contrasting results

This is a though, simple experiment, for thinking efficiently about a real problem much more complicated... Imagine a simple experiment, trying to answer a simple question. For example, is body ...
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0answers
6 views

comparing means for two groups with some overlap

How can I compare the means of two data sets where there is some overlap in the samples so that the groups are neither paired nor independent? That is there has been some change in the samples with ...
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0answers
17 views

Confidence interval and probability mixed [closed]

An advertising agency needs to create a television advertisement for a sun block. The hirer, who makes this product, says that 40% of customers prefers his/her brand. The agency did a survey to verify ...
2
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2answers
43 views

Why do we compare p-value to significance level in hypothesis testing of mean?

I know that: p-value = P(observed or more extreme outcome of sample mean | Null hypothesis is true) But why do we compare it with significance level (alpha) while determining if it is high or low? ...
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1answer
42 views

Confidence intervals vs P-values for two means

I know in studies where relative risk or odds ratio is calculated, if confidence interval overlaps 1, then the P-value is not significant. Is similar relation true for following situations as well? ...
0
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0answers
27 views

Analysis of the Benjamini-Hochberg adjusted p-values

I have: Condition #1 : 5 independent objects (1 object = a time series) Condition #2 : 5 independent objects My GOAL: test H0 that using condition #1 gives different results from using condition ...
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2answers
48 views

two samples z test in Python [closed]

Does Scipy have a z test to compare the mean of two samples? I searched this page but couldn't find one.
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3answers
163 views

Is hypothesis testing methodology based on flawed reasoning?

Hypothesis testing seeks to reject a null hypothesis ($H_0$) on the basis of an assumption made about the sample following a certain distribution. This assumption is conditional on $H_0$ being true. ...
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1answer
13 views

Comparing how good models with binary dependent variable are

So I'm not very well versed when it comes to statistics, so this is a bit over my head. I can't go into too much detail (NDA, etc etc), but I have four different datasets where in every dataset there ...
2
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56 views

Simulation of Monte Carlo test

Using R, I am trying to simulate how the power of a Monte Carlo two-sample test for central tendency changes with sample size. However, my simulation results does not show power increasing with sample ...
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1answer
56 views

Test for comparing graphs of daily activity

I need to compare some (or a least two) graphs of activity of birds, like in the example below. Column “Hour” – it’s a time (8.25 = 8 h 15 min, 8.50 = 8h 30 min, 8.75 = 8h 45 min, etc; column R – ...
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1answer
29 views

null and alternative hypotheses

A group of 50 complete a national fitness test and get a mean score of 80 out of 100. The national average is 72 with standard deviation 6. Can we conclude the group of 50 is fitter than the national ...
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30 views

Comparing two population of non ordinal data (categorical data)

I have 2 dataset $D_1$ and $D_2$ whose elements can assume values between 0 and 1. The cardinality of $D_1$ and $D_2$ is the same. Think for example at the measurement of the temperature in a set of ...
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0answers
20 views

How to account for both between-subjects and within-subjects covariables?

I have a data set I'm trying to analyze and I can't figure out how to include the two different kinds of covariables in my analysis. Without the covariables, the analysis isn't too complicated. It's ...
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1answer
22 views

Chi-squared two sample test for unbinned discrete data

I am wandering through the net but I cannot get a precise description of how to solve this simple task. Two sets of datas ...
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0answers
14 views

Which statistical tests to perform for my survey study?

I'm designing a survey study (with non-probability sampling) with the following alternate hypotheses: Usage of the system varies among the three groups (three groups of unequal sizes) ...
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0answers
20 views

Hypothesis testing on groups of time series data

I have some experimental data from two groups, where each group contains data from $n$ subjects. The data are in the form of a time series for each subject, but are not all the same length. To be ...
2
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1answer
51 views

Difference in 2 groups when group assignment is not certain

Suppose you have two groups and you want to see whether these two groups differ in regards to some variable. This sounds like a basic t-test or perhaps non-parametric Wilcoxon rank sum test. Suppose ...
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16 views

OLS and multiple hypothesis testing

I have a multivariate regression with more than two independent variables. However, I am only interested in two particular variables. So for simplicity, I write this model in terms of the two ...
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1answer
46 views

Exact two sample proportions binomial test in R (and some strange p-values)

I am trying to solve the following question: Player A won 17 out of 25 games while player B won 8 out of 20 - is there a significant difference between both ratios? The thing to do in R that ...
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1answer
24 views

Test if paired data are more similar than non-paired data

I have a set of ten samples, comprised of five pairs of twins, and I have calculated the pairwise distances between all ten samples. The question I would like to answer with this data is: Are ...
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21 views

null hypothesis confusion

Experts argue that at most 30% of schools pupils benefit from homework. A sample is taken. Write down null and alternative hypotheses. I would have thought that the null would be that the number of ...
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27 views

a/b tests show strange results. Can the results tell if the test method has bugs/issues?

I'm running a/b test on an ecommerce website. The current stats look like this: The problem is that the 'rule' does nothing. so basically the two groups should be identical. The selection of ...
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28 views

Hypothesis testing with Neyman–Pearson Lemma

I have hypothesis: $H_0: X\ \sim\ \mathcal{N}(-1,\,1)$; $H_1: X\ \sim\ \mathcal{N}(-9,\,9)$. Also I have significance level $\alpha = 0.2$. I'm checking them by Neyman-Pearson Lemma. 1) Find ...
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4answers
159 views

How to choose the null and alternative hypothesis?

I'm practicing with the hypothesis test and I find myself in trouble with the decision about how to set a null and an alternative hypothesis. My main issue is to determine, in every situation, a ...
2
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1answer
64 views

How to compare the proportion female with the proportion male

I would like to know if it is correct to do the following statistical comparison: In a sample of $440$ patients, I have $241$ females ($54.8\%$) and $199$ males ($45.2\%$). Are these proportions ...
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1answer
44 views

Good venue to find online tutor in mathematical statistics?

I've been having trouble finding a qualified online tutor to work with me on NHST vs. Bayesian concepts and experimental design. I'm sure there must be people around & available with real chops in ...
2
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1answer
48 views

Inconsistent outcomes of boostraped hypothesis tests on max and median

I am trying to make an hypothesis test using bootstrapping. I compute a quantity Q from a sample set (the exact calculation should not be relevant, but let's say ...
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0answers
6 views

UMP test for two different distributions

My question: UMP test for H0: X~u(0,1) vs H1: X~Exp(1) My attempt : By nayman pearson lemma The best critical region is Y >= c Where Y has Irwin-Hall distribution (sum of uniform distribution) and c ...
5
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2answers
48 views

Appropriate method for determining difference between means?

I'm looking at the calling rate of bird species when prey availability is altered. So there are two groups, a control (no manipulation) and experimental group (where prey has been increased). I'm ...
0
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0answers
14 views

Validating sameness or difference of a relationship

I am measuring a response variable Y(x,t) which theoretically is a function of both time (t) and space (x). I have measurements for Y as t varies for different spatial points x. On inspecting visually ...
3
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0answers
26 views

Paired test using GLM with Gamma distribution

I know, that a paired T-test can be formulated in the framework of a linear model for gaussian distributions. I have two vectors of paired mesurements (rates under certain conditions) that follow a ...
4
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1answer
58 views

ANOVA-type test but with known population variance of each group

I have a set of $N$ samples $s_{i}$, each one sampled from a normal distribution with standard deviations $\sigma_i$, which are known. I would like to know if the distributions have the same mean. I ...