All Questions
Tagged with hypothesis-testing inference
453 questions
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Estimate SD[Z=X*Y] which one is correct?
Given we have a sample of two variables X and Y with sample size n. I want to calculate the standard deviation of Z = X*Y. I don't know which of the two options bellow are correct?
Option 1:
Simply ...
- 193
1
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0
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12
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Nonparametric extrema hypothesis test based on ranks
Does there exist a non-parametric test testing the following hypothesis:
given $N$ points in $\mathbb{R}^m$ and their ranking $Y$ in $\mathbb{N}$ answer:
$H_0:$ there is no minimum or maximum (extrema)...
- 41
1
vote
1
answer
28
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How to Calculate the Confidence Interval of the Sampling Mean with Scale Sensitivity and Varying Sample Sizes?
I am currently facing a statistical challenge while comparing the average weights of two populations of larvae, and I need help figuring out how to perform the analysis correctly given the constraints ...
2
votes
1
answer
22
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statistical method for analysis of multiple related variables affecting 1/2 outcomes
I am going to abstract this question to conceal my actual research contents, but I am an absolute noob in statistical analysis, and I would like to learn more from the gods of this website.
I am ...
- 21
0
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0
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19
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Hypothesis testing a property of parameters
Suppose I have $n$ i.i.d observations $X = (X_1,X_2,\cdots,X_n)$ generated from some distribution $p(x;\theta)$ where $\theta \in \mathbb{R}^m$ is an unknown parameter I would like to infer from ...
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0
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12
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How to define power in case of multiple tests that complements with family-wise error rate?
Family-wise error rate is defined as the probability of rejecting at least one true null hypothesis, that is, the probability of committing at least one Type-1 error.
How do we define the power in ...
- 211
1
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2
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87
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What hypothesis test should be used for two categorical variables in Likert scale?
I'll give an example.
Let's say I conducted a health survey in a hospital. I asked two questions. The first question is: 'I take medication to sleep well' and the second is: 'I feel unwell in the ...
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22
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7
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2k
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Isn't it problematic to look at the data to decide to use a parametric vs. non-parametric test?
I've seen in some instances of people mentioning that using a parametric vs. non-parametric approach may be decided by looking at the data. For example this question: nonparametric vs. parametric
Isn'...
- 243
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0
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32
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Sufficient number of data to determine whether a model fits the data well
I was wondering if, chosen a proper mathematical model, there is a minimum number of data that allows us to state if the model fits well the data or it doesn't.
I'll explain better my question. Let's ...
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3
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1
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46
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Can/should a scientific paper simultaneously perform one-sided hypothesis testing and a two-sided confidence interval?
Let's say you wish to perform a one-sided hypothesis test in which you want to reject $H_0: \Delta \leq 0$ in favor of $H_1: \Delta >0$. You select this hypothesis test specifically because you are ...
6
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3
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426
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The rationale for when significance or null hypothesis testing is needed
Why do people sometimes claim that an effect is so huge and "obvious" that it does not warrant any inferential statistics calculation, even though the sample size is not large?
This is ...
- 175
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13
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For a test of sample means, is it fine to use a z-distributed test statistic if the standard error is estimated through bootstrapping?
In an online course I'm taking, for a hypothesis test (one sample test of sample mean), we use a z-statistic instead of a t-statistic (the population variance is not known). The reasoning being ...
- 787
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1
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93
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Which statistical test should I use for 3 independent variables and one dependent variable?
What are the tests that I can use for 3 independent variables (ordinal - Likert) and 1 dependent variable (college grades - general average)?
I am trying to see if the IV really affects their GWA (DV) ...
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1
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1
answer
46
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Which technique to use for models that include Likert-scale items?
I have three or more independent variables (a Likert scale was used) and GWA as my dependent variable, to see what variables are influencing student compliance with respect to a school's grade ...
- 11
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0
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50
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Second Generation P-values in the Context of Statistical Evidence and Sample Size
I am currently doing research on statistical analysis, and I have come across the concepts of Second Generation P-values (SGPVs) introduced by Blume et al. I understand that these are used to ...
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35
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Rejection region for the likelihood ratio test (uniform distribution)
Let $x_1 ... x_n$ be sampled from a uniform distribution with $f(x;\theta) = (1/\theta), \theta; >0, x \in [0,\theta].$
After finding the likelihood function for the hypotheses:
$H_0 : \theta = \...
0
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1
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41
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Within subject experiments done by (some) Psychologists
Thanks in advance for any responses or resources you can link me to.
I've had more of an Econ/Stats training and recently I've been working with some people who have a Psych background at work.
They ...
0
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1
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65
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What statistical tests to use for multiple datasets?
I have calculated the species richness of mammals in 10 sites, for different variables. For example, I have the species richness of carnivores, omnivores, herbivores etc in one analysis group, and ...
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2
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2
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58
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Correct interpretation of an Unbiased Test
The definition in the book I am reading says the following:
A test with power function $\beta(\theta)$ is unbiased if $\beta(\theta') \geq \beta(\theta'')$, $\forall \theta' \in \Theta_{0}^{\...
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1
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1
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55
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Comparing sequence of unfair coin flips with different predicted probabilities
Suppose we have $n$ independent coins, each of which has an unknown and different probability of coming up heads. We have a magical machine that guesses the probabilities of each coin coming up heads. ...
13
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8
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2k
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Is descriptive statistics enough to compare test scores of students in a class?
I am reviewing the theory on hypothesis testing and the book I am reading ("Hypothesis Testing" by Jim Frost) stresses the fact that we do hypothesis testing and inferential statistic when ...
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1
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1
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47
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How many samples should I test to be 95% sure that no error exists?
If I have a million population of products and I will tolerate no error in them. How many samples should I test to be 95% sure that no error exists?
I am new to statistics. I know you might need some ...
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2
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1
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155
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Deriving Sample version of Anderson Darling test statistic from the theoretical version
In literature, I have seen two types of Anderson-Darling test statistic. One is expressed as
$A_T^2 = n\int_{-\infty}^{\infty}\frac{(F_n(x)-F(x))^2}{F(x)(1-F(x))}dF(x)$ and the other is given by $A_s^...
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3
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1
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80
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How do data/observations themselves contribute to our ability to make determinations of whether a hypothesis is true or false?
Let's say that I have a hypothesis, and I'm trying to determine whether the hypothesis is true or false. If I remember correctly, in statistics, the standard philosophical view is that, technically, ...
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2
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1
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238
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Karlin-Rubin theorem: relationship between test statistic having the MLR property vs being sufficient
Let's suppose we are trying to compare two hypotheses for a single parameter $\theta$. The null hypothesis $H_0$ is that $\theta = \theta_0$, and the alternative is that $\theta ≥ \theta_0$.
The ...
- 475
1
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1
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53
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Can we do a reasonable statistics interpretation on A/B test if group size is not known
My coworker did A/B test finding a 6.5% diff in two groups conversion rates. First group has 1176 converted events and second group 1309 converted events.
The total number of events before conversion ...
- 11
0
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0
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35
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Choosing Null Hypothesis [duplicate]
I am studying Hypothesis Testing, I see that my instructor used to put the equal sign in the null hypothesis for all examples, this makes me confused about how to choose the null and the alternative ...
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1
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62
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How to perform inference in a simple mediation analysis?
I am running a very simple version of a mediation analysis with five variables, $y, x, t, z1, z2$. It's simple in that I am only including the mediated effect.
I first run $y = x + t + e1$. Next, I ...
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1
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23
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How to formulate this problem when analysing "choose up to X items" survey results
I have these survey results that came from the marketing team in my company. The survey has a few questions that you can choose up to 3 or 5 items from a list. I don't know the name of this kind of ...
0
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0
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51
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What is the maximum allowed sample size for two sample t-test in pingouin library? [duplicate]
I'm currently running a test to compare the performance times of our new and old machines. Working with a substantial dataset—over 50,000 records—that leans toward the new machine being faster. ...
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0
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1
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114
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comparing two samples drawn using two different sampling methods
This is a hypothetical question, so I don't have a lot of additional details to give. However my question is pretty straightforward:
Is it theoretically valid to conduct tests (e.g. for comparing ...
- 57
1
vote
1
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72
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p-value comparison
Is it possible to compare two p-values? Suppose for a test with significance level 0.05, I get p = 0.06, and for another test with similar data, I get p = 0.20. What can I say if I want to make ...
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2
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2
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386
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How to understand that there are n - 1 degrees of freedom in calculating sample variance? [duplicate]
According to Wiki:
In statistics, the number of degrees of freedom is the number of values in the final calculation of a statistic that are free to vary.[1] Estimates of statistical parameters can be ...
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5
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2
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337
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Should the Wilcoxon Rank sum test be used for testing the mean difference significance?
I was looking replicate the results of the paper DOI:10.3905/jpm.2014.40.3.087 (Exploring Macroeconomic Sensitivities: How Investments Respond to Different Economic Environments, Ilmanen Maloney Ross ...
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2
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2
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251
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Regression coefficient before vs. after demeaning X
It is well known that $\beta = (X^{T}X)^{-1}X^{T}Y$ for linear regression. While experimenting with this, I found that $\beta$ (excluding the intercept term) remained the same before and after ...
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2
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1
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530
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Is Power Function the same as Probability of Type I error?
I am currently reading Casella & Berger and at Paragraph 8.3.1 Error Probabilities and the Power Function It says the following:
Suppose $R$ denotes the rejection region for a test. Then for
$\...
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2
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1
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75
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Can evidence of absence be obtained only in one-sided hypothesis tests?
It seems that if a one-sided Z-test returns a p-value $>1 - \alpha$, you have enough evidence of absence to reject the alternative hypothesis in favor of the null hypothesis, because if you were to ...
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2
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0
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177
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finding the UMPU test
When trying to find the uniformly most powerful unbiased (UMPU) test for the exponential family Lehmann and Romano give a "simple" approach.
Suppose that we want to test $H_0: \theta = \...
- 1,455
1
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1
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100
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Two sample proportions: How to test the hypothesis that the difference in proportions is less than a specified threshold?
Say I have treatment and control, perfectly randomized.
I have 70000 conversions for treatment in 80000 users.
I have 70100 converions for control in 800100 users.
My null hypothesis is that there is ...
0
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0
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20
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Which statistical test to apply to calculate if a difference is significant between annotations?
I have the following problem: I have a text which needs to be annotated with named entities. I have two annotators who have annotated the text twice. How can I calculate if the change in the number of ...
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56
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If we know the exact value of the population parameter , is there any point in doing the hypothesis testing? [duplicate]
Question - In a year there are 956 births in a town A of which 52.5% were males, while in town A and B combined, this proportion in a total of 1406 births was 0.496. Is there any significant ...
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0
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38
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Generalized likelihood ratio test for a left-truncated exponential distribution [duplicate]
I am doing self study in statistical inference and am rather confused about how to approach generalized likelihood ratio test (GLRT) problems. I am trying the traditional approach by definition and ...
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0
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75
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Wald Test on two exponential samples
Based on independent samples of data $X_i \sim$ Expon$(\lambda_1)$, $i = 1, \cdots, n,$ and $Y_j \sim$ Expon$(\lambda_2)$, $j = 1, \cdots, n$ (both samples of the sample size $n$), find the Wald test ...
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4
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1
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153
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Do I need a hypothesis test to compare two populations of complete annual count data?
I would like to compare the total number of public M&A transactions observed in two separate years (e.g. 2021 vs 2022). Given the data set for each year is complete (i.e. a population), can I ...
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1
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0
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126
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ordinal data negatively skewed. Help me :( [closed]
I'm working on my masters dissertation. Please help me this is my very first ever quantitative research and my submission deadline is very soon and my brain is literally melting into soup :(
1- Data ...
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1
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144
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How to use VAR model for model forecasting
Good evening, everyone.
I am a software engineer and I am studying the VAR model and its advantages and disadvantages. Specifically, my question is the following: is it possible to use VAR to predict ...
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180
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Define and Remove outliers from a Pareto-like Distribution
I currently have a set of data:
1 40950
2 27749
3 14786
.........
15 95
16 75
..........
12205 1
15344 1
19991 1
The first column ...
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1
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43
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How to analyze temporal effect on outcomes in two populations
I'm looking for guidance for how to plan an analysis. I am interested in temporal differences amongst two different populations. More specifically I'm interested in assessing differences in length ...
2
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0
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90
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Compare beta coefficients from two different Poisson models
I would like to compare two beta coefficients from two different Poisson models which have the same variables and applied to different samples. I would like to test their difference to check if the ...
- 151
1
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0
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73
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Comparing means on aggregated data
I'm confused about how to compare means given the following scenario. Suppose a company has stores in 2 countries, CA and US, which each get some number of Customers...
- 111