Tagged Questions
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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8
votes
3answers
292 views
Mean$\pm$SD or Median$\pm$MAD to summarise a highly skewed variable?
I'm working on highly skewed data, so I'm using the median instead of the mean to summarise the central tendency. I'd like to have a measure of dispersion
While I often see people reporting mean ...
4
votes
3answers
3k views
Why is the arithmetic mean > median on a histogram skewed to the right?
I am fairly new to statistics.
Currently I am into (histograms) medians, arithmetic mean and all the general basics.
And I came accross the fact/rule that the arithmetic mean is (always) larger than ...
3
votes
1answer
96 views
Why is the expected value of the number of trials before the first success larger than the number of trials with a 50% probability of success?
For a Bernoulli distribution with parameter p, the number of trials with a 50% probability of at least one success is about (1/p) * ln(2). But the expected value of the corresponding geometric ...
