Questions tagged [percentage]

Number or ratio expressed as a portion of 100

A percentage is a number or ratio expressed as a fraction of 100. It is often denoted using the percent sign, "%".

The word "percentage" goes back to the latin words "centum" which mean 100 in English. "Per centum" can be literally translated as "from hundred".

Often percentages are depicted as pie charts summing up to 1, i.e. 100 %. Often a percentage is also used to show a relative change, e.g. in 2013 the GDP growth rate in the USA was 2.2 percent which mean that:

GDP USA 2013 = 102.2 GDP USA 2012

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Percentile vs quantile vs quartile

What is the difference between the three terms below? percentile quantile quartile
luciano
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Why is 600 out of 1000 more convincing than 6 out of 10?

Look at this excerpt from "The study skills handbook", Palgrave, 2012, by Stella Cottrell, page 155: Percentages Notice when percentages are given. Suppose, instead, the statement above read: 60% of people preferred oranges; 40% said they…
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Is 50% 100% higher than 25% or is it 25% higher than 25%?

If I have two values A and B which are both expressed as a percentage of C, and I want to express the difference in magnitude between A and B as a percentage D, is it more correct to express D as a percentage of C, or as a percentage of B (or indeed…
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What kind of curve (or model) should I fit to my percentage data?

I am trying to create a figure which shows the relationship between viral copies and genome coverage (GCC). This is what my data looks like: At first, I just plotted a linear regression but my supervisors told me that was incorrect, and to try a…
teaelleceecee
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Using ANOVA on percentages?

I have a table with four groups (4 BMI groups) as the independent variable (factor). I have a dependent variable that is "percent mother smoking in pregnancy". Is it permissible to use ANOVA for this or do I have to use chi-square or some other…
drew
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What are the issues with using percentage outcome in linear regression?

I have a study where many outcomes are represented like percentages and I'm using multiple linear regressions to asses the effect of some categorical variables on these outcomes. I was wondering, since a linear regression assume that the outcome is…
Bakaburg
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Example distribution where 74% of probability is above the mean

Watching Why You Should Want Driverless Cars On Roads Now, at 8:14 Derek Muller claims: Surveys show 74 % of people believe they are above average drivers. This claim motivates my question, but some clarification is needed. I am not asking for…
DifferentialPleiometry
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How can percents not adding up to a hundred be possible?

I was reading this paper about aquaponics and some of the stats did not make any sense with regard to the percents listed. What method would allow these percents to exist? The most commonly raised aquatic animals by percent were tilapia (69%),…
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Mixture of beta distributions: full example

I have a vector of measured proportions and want to test if these proportions follow a bimodal distribution characterize the two underlying distributions determine for each data point which distribution it belongs to overaly the density…
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Why can I interpret a log transformed dependent variable in terms of percent change in linear regression?

Looking at resources such as this one and this one, you see claims like "Exponentiate the coefficient, subtract one from this number, and multiply by 100. This gives the percent increase (or decrease) in the response for every one-unit increase in…
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Can a standard deviation of raw scores be reported as a standard deviation of percentages?

Suppose we have a test consisting of 30 questions, and 10 people take this test. The mean test score of these 10 people is 17, and the standard deviation of all the scores in the sample is 4. When reporting the descriptive statistics at school, we…
Freya
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Is it correct to model percent change as a continuous variable?

I have data from a longitudinal study where there are 46 subjects, each with 13 observations over time on a given outcome measure. A prior analysis conducted on this data performed a linear mixed model on the percent change (treatment, baseline…
Bosley
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Dungeons & Dragons Attack hit probability success percentage

In D&D players roll a 20 sided die trying to beat a set number to determine if an attack hits the target. Players often can add modifiers to this roll to help the odds in reaching this target number. If the target number (enemy armor level) is…
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What regression model to use when independent variables are percentages to predict % outcome?

"Independent" variables: time spent (% at work, % sleeping, % exercising), body mass composition (% fat, % muscle, % bone) Dependent variable: Smoker (1) or Non-Smoker (0) What kind of regression model should I use when subsets of the "independent"…
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How many tests should we do to estimate the percentage of people who contracted COVID-19 in Lombardy?

Lombardy, a region of Italy, registered many severe cases of COVID-19 in the last few months. Unfortunately the available data don't allow us to estimate the percentage P of people who contracted the virus in Lombardy (please don't dispute this, but…
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