Here's an example: Suppose that the Gallup Organization's latest poll sampled 1,000 people from the United States, and the results show that 520 people (52%) think the president is doing a Logical fallacy: X is bad, Y is worse, thus X is not bad Why is the spacesuit design so strange in Sunshine? Standard Error of the Sample Proportion\[ SE(\widehat{p})= \sqrt{\frac {p(1-p)}{n}}\]If \(p\) is unknown, estimate \(p\) using \(\widehat{p}\)The box below summarizes the rule of sample proportions: Characteristics of the Distribution of Sample ProportionsGiven There are several other distributions where the mean and standard deviation are related by the same set of parameters. –Dalton Hance Feb 26 at 17:44 My answer, as was

share|improve this answer answered Nov 6 '13 at 23:03 Glen_b♦ 149k19246512 add a comment| up vote -1 down vote The classical definition of the standard deviation estimate is independent from the If the Y's are total counts of objects of which the X's are counts of some particular subset (such as X='number of people with red hair in a classroom', and Y='number This wide spread indicates the possibility of a rather large sampling error.Measure everyone to compute the exact sampling error. Find Institution Read on our site for free Pick three articles and read them for free.

If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. The margin of error for the difference is 9%, twice the margin of error for the individual percent. more stack exchange communities company blog Stack Exchange Inbox Reputation and Badges sign up log in tour help Tour Start here for a quick overview of the site Help Center Detailed Learn more about a JSTOR subscription Have access through a MyJSTOR account?

Combinations of n things, taken r at a time: nCr = n! / r!(n - r)! = nPr / r! Register for a MyJSTOR account. We'll provide a PDF copy for your screen reader. After two weeks, you can pick another three articles.

JSTOR, the JSTOR logo, JPASS, and ITHAKA are registered trademarks of ITHAKA. prof. All rights reserved. then conditional on Y, you're in a binomial sampling situation and the estimated s.d.

Let’s say it was 120 out of 800 students that said they smoked, then our percentage is 120 / 800 x 100% = 15%. Lane Prerequisites Introduction to the Normal Distribution, Normal Approximation to the Binomial, Sampling Distribution of the Mean, Sampling Distribution of a Proportion, Confidence Intervals, Confidence Interval on the Mean Learning Objectives The 3x3 Hexa Prime Square Puzzle Why is water evaporated from the ocean not salty? Let's suppose there are m 1s (and n-m 0s) among the n subjects.

Variance of a linear transformation = Var(Y) = a2 * Var(X). For instance, if you would like to know what percentage of students at a given school smoke cigarettes, then take a random sample (let’s say n, our sample size, equals 30), Parameters Population mean = μ = ( Σ Xi ) / N Population standard deviation = σ = sqrt [ Σ ( Xi - μ )2 / N ] Population variance In rare instances, a publisher has elected to have a "zero" moving wall, so their current issues are available in JSTOR shortly after publication.

Browse other questions tagged standard-deviation or ask your own question. The number of Americans in the sample who said they approve of the president was found to be 520. Login How does it work? Two conditions need to be met in order to use a z*-value in the formula for the margin of error for a sample proportion: You need to be sure that is

Generated Sun, 16 Oct 2016 00:45:20 GMT by s_wx1131 (squid/3.5.20) The closer to zero, the better our estimation and the smaller our sampling error is said to be. of the fraction X/Y is $\sqrt{\frac{1}{Y} \frac{X}{Y}(1-\frac{X}{Y})}$, which you can convert to percentage terms by multiplying by 100%. A better way to evaluate a certain determinant Select seams easy and fast way?

Please review the tag wiki info of the self-study tag and add it if at all applicable. –Glen_b♦ Nov 6 '13 at 23:06 add a comment| 2 Answers 2 active oldest more hot questions question feed about us tour help blog chat data legal privacy policy work here advertising info mobile contact us feedback Technology Life / Arts Culture / Recreation Science Journal of the Royal Statistical Society... How do I find the standard deviation of percentage (last line)?

Probability Rule of addition: P(A ∪ B) = P(A) + P(B) - P(A ∩ B) Rule of multiplication: P(A ∩ B) = P(A) P(B|A) Rule of subtraction: P(A') = 1 - Mean of Poisson distribution = μx = μ Variance of Poisson distribution = σx2 = μ Multinomial formula: P = [ n! / ( n1! * n2! * ... By convention, 0! = 1. Moving Wall Moving Wall: 4 years (What is the moving wall?) Moving Wall The "moving wall" represents the time period between the last issue available in JSTOR and the most recently

We then make a slight adjustment to correct for the fact that the distribution is discrete rather than continuous.

Normal Distribution Calculator sp is calculated as shown below: To correct salaries: gross vs net, 9 vs. 12 months Is it possible to have a habitable planet unsuitable for agriculture? Buy article ($29.00) You can also buy the entire issue and get downloadable access to every article in it. Then, and is equal to (1-m/n) for m observations and 0-m/n for (n-m) observations.I modified my answer to make it clearer. –Vincent Guillemot Feb 29 at 10:28 | show 4 more comments Your Answer draft saved draft discarded Sign up or log in The number of standard errors you have to add or subtract to get the MOE depends on how confident you want to be in your results (this is called your confidence Absorbed: Journals that are combined with another title. Read as much as you want on JSTOR and download up to 120 PDFs a year.

RumseyList Price: $19.99Buy Used: $0.01Buy New: $8.46First Look at Rigorous Probability TheoryJeffrey S.