Questions tagged [percentage]

Number or ratio expressed as a portion of 100

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170 votes
4 answers
205k views

Percentile vs quantile vs quartile

What is the difference between the three terms below? percentile quantile quartile
luciano's user avatar
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41 votes
10 answers
10k views

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: ...
Juya's user avatar
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23 votes
4 answers
11k views

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 ...
Gormen Ghast's user avatar
21 votes
4 answers
67k views

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 ...
drew's user avatar
  • 211
20 votes
7 answers
4k views

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 ...
teaelleceecee's user avatar
18 votes
3 answers
30k views

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, ...
Bakaburg's user avatar
  • 2,907
12 votes
6 answers
2k views

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 ...
Galen's user avatar
  • 8,402
10 votes
4 answers
2k views

How to compare -50% and +100%

This might seem (and be) a really trivial question! I have this table: ...
Lenn's user avatar
  • 233
10 votes
1 answer
9k views

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 ...
user3464896's user avatar
9 votes
1 answer
6k views

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 ...
HSchmale's user avatar
  • 201
9 votes
1 answer
6k views

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 ...
Data's user avatar
  • 484
9 votes
2 answers
8k views

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 ...
Bosley's user avatar
  • 549
8 votes
4 answers
3k views

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 ...
Phillip Byram's user avatar
8 votes
1 answer
2k views

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 ...
Freya's user avatar
  • 165
7 votes
2 answers
5k views

Is correlation a percentage?

The Pearson correlation coefficient ranges from -1 to 1. Oftentimes, people take this number, multiply it by 100 and call it -17.3% correlation or 63% correlation I was once dinged by reviewers ...
MWB's user avatar
  • 1,327
7 votes
1 answer
281 views

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 ...
user7669's user avatar
  • 319
7 votes
5 answers
15k views

How to convert sport odds into percentage?

I am wondering how to convert sport odds to the percentage format. There's this example: ...
user984621's user avatar
7 votes
2 answers
13k views

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 ...
jc11's user avatar
  • 71
7 votes
3 answers
46k views

Is it incorrect to calculate the mean and standard deviation of percentages?

My data is some percentages on how many transactions from a whole are missed each month. The percentages are for 13 months and ranging from 97 to 99 percent. I was asked to calculate the mean and ...
daneshjai's user avatar
  • 171
6 votes
1 answer
474 views

Deal with percentage data

For instance, I have such data: ...
juanli's user avatar
  • 465
6 votes
1 answer
899 views

How do I test difference in Percentages?

I have some survey data and know the number and percentage of "yes" responses. How do I determine if any of the percentage yes regional responses are statistically different from the national yes ...
Mark Hollinsworth's user avatar
5 votes
4 answers
49k views

Should percentages be reported with decimal places?

When presenting data using a percentage, is it a good thing to have decimal places, say 2 decimal places instead of rounding off to whole numbers? For example, instead of 23.43%, you round off to 23%....
Julius A's user avatar
  • 203
5 votes
2 answers
4k views

How to interpret a regression coefficient of an independent variable expressed as a percentage?

I fitted a continuous dependent variable against two explanatory variables. However, one of the explanatory variables is expressed as a percentage. Consider the regression model: $y = 0.05 + 0.032x_1 +...
iGada's user avatar
  • 217
5 votes
3 answers
793 views

Adjusting round-off error so as to have percentages that sum up to $100$

I have non-negative numbers $x_1, \dots, x_n$. These numbers are all percentages rounded to the nearest tenth of a percentage. Unfortunately, I don't have any of the numerators or denominators driving ...
Clarinetist's user avatar
  • 4,957
5 votes
1 answer
211 views

How can I calculate a relative measure of change for data series that can include zero?

I have a series of data points representing the number of OKs for a test. For each data point, I want to calculate by how much its value changed compared to the preceding value, and I need this ...
Mr Kartofel's user avatar
5 votes
1 answer
377 views

Shift the mean of a (not) normal distribution but keep same scale

Warning: I am not a statistician, so please go easy! I have a (not) normally distributed measure of a population, with possible values from 0 to 100%. Its mean is 60%. I need to be able to shift the ...
user176504's user avatar
5 votes
2 answers
17k views

T-test on percentage values (among experimental replicate values)

My experiment involves looking at the precentage of cells in a slide that have a particular property under condition A and condition B. I have one slide for each condition. I have done this experiment ...
user930916's user avatar
5 votes
1 answer
2k views

How to test if a percentage is significantly higher than 0?

I have asked people to rate different items between 0 and 100. On one condition, most of the items were rated very low. Therefore, the distribution of the result looks like an negative exponential. ...
Jennifer's user avatar
5 votes
1 answer
5k views

Percentages as the response variable in GLMM (glmer), proportional binomial or not?

After looking through several questions on stackexchange, and even applying many of the suggested methods I have come to a point where I would like to have an expert's advice if the methods applied on ...
Frederic de Schaetzen's user avatar
5 votes
1 answer
20k views

How to calculate the Standard Deviation of a set of Percentages

I would like to know how to calculate the standard deviation (SD) of a set of percentages. Let me explain better. Some students performed a test and I counted the number of right answers for each ...
Soso's user avatar
  • 51
5 votes
0 answers
187 views

Which approach can be used to regress sleep time on brain mass, in this data set?

I was reading this blog post: https://htmlpreview.github.io/?https://raw.githubusercontent.com/avehtari/BDA_R_demos/master/demos_rstan/sleep.html the author describes a model to predict how many ...
DeltaIV's user avatar
  • 17.9k
5 votes
0 answers
744 views

Percentile vs Percentile rank

I have the read the definitions many times and I still don't quite understand the difference. This article says: A statement such as: "A score of 600 has a percentile rank of 80" has a ...
Josh's user avatar
  • 4,448
4 votes
2 answers
340 views

Win Percentage Question

I have noticed my gambling win percentage (in online pool) is very hard to increase as time goes by. After 1500 games, I'm stuck at 57%. If I want to increase my overall win percentage to 60% after ...
Dan's user avatar
  • 41
4 votes
1 answer
22k views

Chi Square Analysis Percentages

I've used chi-square analysis in school, but was absent for the lesson, and I never quite got the hang of it. I've been successful with it in the past, but now I'm trying to use percentage values, and ...
user2956947's user avatar
4 votes
1 answer
3k views

Power Calculations using "Percent Change" vs. "Absolute Values"

Percent change can be extremely misleading for a number of reasons (e.g. regression to the mean), even though in the medical literature percent change is used quite frequently to "normalize" clinical ...
Vance L Albaugh's user avatar
4 votes
1 answer
424 views

Judging the quality of a statistical model for a percentage

I have a data set with multiple predictors, and a single response variable which is a percentage, thus is bounded between 0 and 100. I cannot share the dataset unfortunately. I would like to build a ...
DeltaIV's user avatar
  • 17.9k
4 votes
1 answer
1k views

Is it possible to find the 99th percentile using other percentiles?

I have the 10th, 20th, 25th, 30th, 40th, 50th (I assume this is the same as the mean), 60th, 70th, 75th, 80th and 90th percentile values of a data set. This is for the distribution of salaries in the ...
Tadiwa Mahlunge's user avatar
4 votes
2 answers
2k views

How to analyze percent data when most of the data is 0%?

I have a set of percent data on histological abnormalities in fish gills and I need to compare the results between two sites A and B. We analyzed abnormalities in lamellae of a particular gill arch. ...
John's user avatar
  • 41
4 votes
1 answer
9k views

Is taking the median of a set of percentages statistically sound?

I have several sets of data, unfortunately the data comes to me in a "summary" form. My job is to consolidate the several data sources into one general summary. I'm currently using the median to ...
Justin's user avatar
  • 141
4 votes
1 answer
1k views

Comparing a distribution of percentages

I have two populations that I would like to compare, each of which contains N samples. Each sample itself contains many events that can be categorized into 20 different, mutually exclusive, categories....
user109900's user avatar
4 votes
0 answers
61 views

Rank forecasting from uneven samples

Say we have a bag of chocolate balls. There are $I$ different unique colors. Our bag has an unknown number of balls for each color. We want to get a sense of which color people like the most and ...
Amelio Vazquez-Reina's user avatar
4 votes
0 answers
20k views

Comparing two percentages

How would I go about comparing two percentage figures from two different sample sizes? For example: Sample 1 - 10% (220,510 out of 2,205,100) of respondents answered "yes", Sample 2 - 31% (12 out ...
Babich88's user avatar
4 votes
0 answers
677 views

Distribution of percent difference of two normal variables

I have two performance measures in a given experiment that I know to be approximately normally distributed: $X_1\sim \mathcal{N}\left(\mu_1,\sigma_1^2\right)$ $X_2\sim \mathcal{N}\left(\mu_2,\...
Felipe Campelo's user avatar
3 votes
2 answers
1k views

Dealing with Heteroscedasticity in ANOVA

I need to perform an ANOVA on percentages data. I have 3 factors: TREATMENT, SAMPLE and DaysAfterTreatment (DAT). Treatment has 3 levels: Control, A, B. SAMPLE has 2 levels: SampleA, SampleB. DAT has ...
kofm's user avatar
  • 33
3 votes
3 answers
2k views

I know the probability of an event to occur, so how do I find how many times the event must be attempted to get a reasonably chance of success?

If there is a 2% chance of event X to occur, how many times must X be attempted to have a reasonable probability of occurring at least once? What is the formula used called, and how do I solve this?
bob jim's user avatar
  • 33
3 votes
2 answers
4k views

Normalizing sample sizes to identify trends

Every month I send out an email to prospective customers. The client I use tracks the number of recipients and the percentage of the emails that were opened. Here's a sample, there's thousands of ...
je99's user avatar
  • 33
3 votes
1 answer
1k views

Interpreting odds ratio of an ordinal regression when independent variables are negative percentages

I'm trying to express the results of an ordinal regression with a certain "perspective", and I'm confused. My dependent variable is an ordinal representing the progression in a scale of negative ...
greymatter0's user avatar
3 votes
1 answer
1k views

How to properly display changes in percentages over time?

Our company is developing self-learning software that extracts data from documents and enters it automatically into text-fields in some other software, on behalf of the user. These suggestions aren't ...
HashedPassword's user avatar
3 votes
1 answer
900 views

Is it possible to statistically test relationships between counts and percentages?

I have counted adult butterfly numbers over 3 areas and would like to compare these counts with the percentage heather cover on each of the 3 areas. Is this possible? My data looks like this (the ...
Natalie's user avatar
  • 43
3 votes
1 answer
57 views

Can I aggregate several continuous variables into percentages and then compare those percentages between groups?

I have a dataset with the concentrations of several lipids. I'm interested in finding lipids that are altered between two conditions, but the lipids are not indepentent from each other and the ...
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