Tagged Questions
0
votes
0answers
20 views
How to add confidence intervals to describe the variability in monthly samples of data?
The data analyzed here is a sample of individuals collected on a monthly basis. What would be the best way to compute confidence intervals for the monthly sample means, in order to indicate the ...
0
votes
2answers
72 views
Why do we refer to our estimates in terms of precision?
Open any statistics textbook and it will urge the need to check the 'precision of our estimates'.
Take the following random variable:
...
2
votes
2answers
102 views
What should I do when a confidence interval includes an impossible range of values?
Let's say I'm analyzing the mean number of students per class for a school district. The district has imposed a hard limit on the maximum ratio: there can never be more than 30 students in a class. ...
0
votes
0answers
37 views
Calculate proportion among means with variance and CI
I have two groups of samples, with their own mean, SEM, CI.
I would like to calculate the proportion in percentage between the two. Rationing the means is easy but I don't know very well I should I ...
1
vote
2answers
407 views
What is the correct SD to use to get a 95% CI for skewed data?
Let $X = [94, 10, 100, 100, 16, 14, 100, 100, 70, 88, 100, 100, 12, 100, 100, 58, 32, 100, 32, 36, 98, 0, 100, 100, 100]$
where $X$ are students' scores (between 0 and 100), and note many full marks!
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9
votes
2answers
2k views
How do I calculate a confidence interval for the mean of a log-normal data set?
I've heard/seen in several places that you can transform the data set into something that is normal-distributed by taking the logarithm of each sample, calculate the confidence interval for the ...
1
vote
2answers
562 views
How to assess accuracy of phone GPS in measuring distances?
I am a complete stranger to statistics (apart from mandatory courses in college), but lately I ran into an interesting real-world scenario.
Recently I started jogging. I take my GPS phone with me to ...
1
vote
3answers
210 views
Confusion regarding the confidence interval
I have some confusion regarding confidence interval.
I was going through this link http://www.stat.yale.edu/Courses/1997-98/101/confint.htm
It has something like this:
Suppose a student ...
2
votes
1answer
182 views
Real data collection with small population
I performed an actual scientific experiment and I was only able to collect 2 data points. I am wondering what kind of statistical method I can use to analyze the data.
I performed a similar ...
7
votes
1answer
877 views
Confidence interval for geometric mean
As title, is there anything like this? I know how to calculate CI for arithmetic mean, but how about geometric mean? Thanks.
2
votes
2answers
315 views
Question on confidence interval
My mean is 3.454992884900722e+008, and my confidence intervals from three distributions (when compared to the given mean) are:
CI for dist. 1: 1.0e+008 * ...
