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-1
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0answers
15 views

Construct and interpret the 90 percent confidence interval [on hold]

To estimate how many of the 350,000 residents of Peoria desire a new civic center, the mayor finds that 1,570 out of the 2,100 residents sampled expressed support. Help the mayor construct and ...
0
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0answers
3 views

Scoring model/formula to rank based on accuracy of data sources

Let us say i have 5 different data sources. My aim is arrive a score to arrive the accuracy of this data sources. It is like below 1. Refer the section Data confidence calculation in ...
2
votes
0answers
34 views

AB test - Is it okay to use a result with a low confidence level

Suppose you conduct an A/B test of 10,000 views for each of version A and B, but the results take 3 months to capture. Despite a small number of views, achieving a goal (converting a "view" to a ...
5
votes
3answers
781 views

How to choose a confidence level?

I often use a 90% confidence level, accepting that this has a greater degree of uncertainty than 95% or 99%. But are there any guidelines on how to choose the right confidence level? Or guidelines ...
0
votes
1answer
8 views

Difference in confidence intervals of two sample sizes given a finite population

I can't seem to wrap my head around this problem. My company is commissioning a facility that recovers two types of metal from ash generated from an incinerator: ferrous (metal containing iron) and ...
2
votes
1answer
21 views

Confidence interval for polynomial linear regression

I have a model which is not linear but rather polynomial, and I have to estimate the parameters by giving a 95% confidence interval. There are plenty of formulas for regression of the type $Y = ...
1
vote
0answers
18 views

How to decide which of two distributions a sample is from?

I have two random distributions. How can I get a quantitative estimate of the likelyhood that a particular sample was taken from one or the other of the distributions? To be more precise: Let $I = ...
0
votes
1answer
42 views

How do I calculate required Sample Size to get useful confidence interval length for Bernoulli random variables?

I am pulling meta data fields from a population of 100M documents. These meta fields include things like Author Name, Author Location, Keywords, etc. Some documents have all of these meta fields, some ...
1
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0answers
28 views

Combining info from two population coverage levels from a tolerance interval

I have some existing product data from which I've calculated a tolerance interval with a 95% confidence level with at least 95% of population covered. I would like to use this tolerance interval as a ...
0
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0answers
5 views

we have two separate forest plots with data that we wish to combine into a ratio. We were wondering how this is possible

We have a forest plot of FEV1 values at given NO2 exposure and a second plot of FVC values at given NO2 values. We need to make a forest plot of an FEV1/FVC ratio and do not know how this is possible. ...
2
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0answers
28 views

Formula for Confidence Interval for effect size

Do anyone have a formula for calculating Confidence Interval for effect size? I need the hand calculation formula for Confidence Interval for effect size (F-Test)?
0
votes
0answers
23 views

Upper confidence interval for the variance using chi squared distribution

It is needed how to estimate the upper confidence interval for variance. I have the equations here from a document. I attach a photo of one page. I do have the raw data and hence the mean values, ...
1
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0answers
40 views

calculate statistical value of the mean of a mean of a mean

EDITED FOR CLARITY Hello, Considering the picture below each values X could be identified by the indeces X_g_s_d_h ...
0
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0answers
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 ...
0
votes
0answers
21 views

Naive Bayes Produce Confidence

I am pretty newbie in machine learning. Please forgive and point out anyone incorrect use of terminology. Now I am learning Naive Bayes algorithm. As I have learned Neural Network, when predicting, ...
1
vote
0answers
36 views

How to test a claim about a confidence interval (real case)

I need to test a claim made by a company stating that 95% of the cases (passangers per day, peak hour) are processed in 40 minutes or less. 1 - I assume I must collect a passanger sample but how ...
0
votes
1answer
18 views

confidence level in non nested models

I have 7 non nested models: I use the Akaike method to see which one best describes the data. If the models were nested I would use the likelihood ratio test: this woluld also automatically give me ...
1
vote
0answers
27 views

How can I estimate (with confidence intervals) the divergence between two smoothing splines?

I have time series data from two independent groups. I want to know whether these groups diverge over time and, if so, when they diverge and for how long. The way I have done this is to estimate ...
0
votes
0answers
90 views

Confidence interval and confidence band

How are confidence intervals related to the confidence band (in a nonlinear regression problem)? I understand that the term confidence interval is reserved for the parameters involved in a regression ...
0
votes
0answers
13 views

multi variate tests - how to find real confidence

We're running multi variate tests on websites. See actual data below. Basically in a session for each banner we randomly choose whether to show/hide it and calculate conversion rates for the show and ...
0
votes
0answers
22 views

Fusing probability scores from different independent sources

Consider a situation where two independent sources, $s_1$ and $s_2$ are giving probability estimates regarding the occurrence of a event $e$. I tried to model this as a bayesian network but that ...
1
vote
0answers
19 views

Is confidence transitive in asociation rules?

Given a set of rule such as: $A \rightarrow B$; $B \rightarrow C$; that satisfy minimum confidence in the context of apriori algorithm meaning: $$\text{Conf}(A \rightarrow B) \geq \text{min. ...
0
votes
0answers
21 views

Binary event probability optimization

I have a relatively small sample of binary events (50-100 events) that occurred during a time of day (the success rate is closely related to the time of day). I'm grouping these events into hour ...
1
vote
0answers
40 views

Estimate confidence in multiple choice test

There is multiple-choice test and for every possible answer option my algorithm gives some score of how much it is likely to be the right one and picks the one with the maximal value as the answer. ...
1
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0answers
16 views

Confidence size and coverage probability in a confidence set?

Let $\theta \in \Theta \subseteq \mathbb{R^d}$ be the parameter of interest and let $\theta_0$ be the true population parameter value. Let $n$ be the sample size. Let $CS_n$ be the confidence set ...
3
votes
1answer
59 views

How to correctly understand confidence intervals and confidence level [duplicate]

I recently read an online discussion about confidence levels and confidence intervals. To be honest, I'm confused. What's the bottom line there? For a specific statement, say, Foobar is 3.45 ...
2
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0answers
32 views

Analysis of proportions over time

My knowledge of statistics is limited and I am looking for resources to read on the matter if possible. Anyways, I am currently trying to estimate a confidence interval for a proportion over time. ...
4
votes
1answer
448 views

How to get confidence on classification predictions with multi-class Vowpal Wabbit

I have a classification problem in which I'm using the --ect option for the multi-class algorithm. The output of the classifier is something as follows: ...
1
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0answers
33 views

Regression problem

Regression was estimated using OLS. We get y=a0 + a1x1 + a2x2 + error. We know covariance matrix ∑ of our estimator. 1. How to get confidence interval for a1/a2 ratio? 2. In what case would the ...
1
vote
1answer
10 views

Avoid rater tendency in confidence questionaires

For the development of a new chemical process, a handful experts should be asked a few questions (4 to 6), what values they expect for several experimental parameters, i.e. temperature ranges and how ...
2
votes
1answer
34 views

Correct expression of confidence level

A very basic question: when noting the statistical significance of fitting some model, does one report that results are significant at the 95 percent confidence level, or at 0.05 significance?
3
votes
3answers
109 views

Joint Confidence Interval

Given the following model: ${\rm Wage}_i=\beta_0+\beta_1 {\rm Married}_i+\beta_2{\rm Female}_i+\beta_3 {\rm Married}_i \times {\rm Female}_i + \varepsilon_i$, I am interested in finding ...
0
votes
3answers
487 views

confidence intervals for values estimated from the nonlinear regression model

I have a question about nonlinear regression and confidence intervals for values estimated from the model. Here is my problem. I have sets of data where $X$ is the logarithm of the dose of a chemical ...
3
votes
2answers
67 views

Comparing Bernoulli means across subpopulations in which the number of observed successes may be zero

I've got a binary characteristic and a population $S$ with size $n$ and $P[X] = p$ such that $p$ may be small and $n$ is extremely large. Within this population are subpopulations of various sizes ...
0
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0answers
58 views

Linear regression slope confidence interval - how to choose a cutoff with few points?

I am performing a large number of linear regressions (around 2000) through the origin. Each regression is on a different number of points (between 2 and 1000), and I am using robust regression (with ...
2
votes
1answer
62 views

Why are intervals for means narrower than intervals for individual observations?

I am looking at problem 5.01 relating to Galton's data on adult heights of fathers and sons, from Chapter 5 of Statistical Modelling: A Fresh Approach link to this book: ...
1
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0answers
123 views

Computing Confidence in A/B testing

First of all, I'm fairly new to Decision Theory and my question might be rather too simple for the experts. I am having some issues in computing confidence for A/B Testing. I will first explain the ...
2
votes
2answers
212 views

Confidence limits for a nonlinear regression

I've fitted some weighted data to a nonlinear model (namely a Sèrsic light profile), using least squares. That is, I have fitted a weighted nonlinear least squares model of the form: $$I_r = I_0 ...
2
votes
1answer
42 views

Prove Confidence of Rule

Using Association. I want to prove the confidence of the rule $B'->(A\B')$ can't be more than the confidence of $B->(A\B)$ Given: frequent itemset $A$ and subsets $B$ of $A$. $B'$ is a ...
0
votes
1answer
58 views

confidence band multiple regression [closed]

I have realized a multiple linear regression with R. When I realize the graphs diagnostics, I would like to draw the confidence band along with the loess curve in the first plot (residual vs. fitted ...
1
vote
1answer
63 views

Combining results with different confidence levels

I have an experiment where I throw a biased coin were with confidence interval [0.38, 0.42] and confidence level of 0.95 I will get heads. If I get heads then I throw a biased 6-sided die which gives ...
1
vote
1answer
777 views

How do you derive the Success-Run Theorem from the traditional form of Bayes Theorem?

In my industry it is common to test a sample of 20-30 and then use that data to draw conclusions about the reliability of the product with a certain confidence. We have tables for such things but it ...
5
votes
1answer
115 views

Confidence interval on R-squared

I know that it is possible when you realize a multiple linear regression to calculate the confidence interval on the R-squared and on the adjusted R-squared. Does somebody know how to do it with R?
2
votes
1answer
243 views

sample size to get 99.6% confidence on a one-tailed test

If I have a normally distributed population of 3.5 million elements, and I want to sample enough of them to make a statement with 99.6% confidence on a 1-tailed test, what should my sample size be? ...
0
votes
1answer
76 views

Regression confidence on new data point

I'm in the process of building a prediction system, and one of its requirements is to be able to give the confidence of a prediction. That is, given a set of independent variables, it should be able ...
1
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0answers
442 views

Creating summary tables / graphics in R for categorical data [closed]

I am trying to summarise data from a household survey and as such most of my data is categorical (factor) data. I was looking to summarise it with plots of frequencies of responses to certain ...
4
votes
2answers
208 views

Calculating when significance will be reached in A/B test ($\chi^2$ test of the difference between two proportions)

I'm a marketer trying to understand the math involved in A/B testing. I've come across a tool that estimates how many more samples are required to reach significance for a test that's already begun. ...
0
votes
0answers
79 views

Rpart confidence interval

Is there any way to compute 95% confidence intervals and prediction interval for the predicted value at each node? Thanks!!!
0
votes
1answer
158 views

Confidence Score for a Single Proportion [duplicate]

I was asked to calculate a confidence score for a single proportion representing a conversion rate. I saw a lot of documents that calculate confidence intervals for proportions based on the binomial ...
1
vote
1answer
68 views

Bivariate conditional probability confidence

I have two random variables following normal distributions, $X\sim N(\mu_{x},\sigma_{x})$ and $Y\sim N(\mu_{y},\sigma_{y})$ I know the covariance is $\operatorname{Cov}(X,Y) = c$. And I believe ...