Estimated Margin Of Error Calculator Using Confidence Interval
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find the use the given confidence interval to find the margin of error and the sample mean margin of error and the sample mean: (0.256,0.380)
Confidence Interval Margin Of Error Formula
a.The margin of error is: _____ b.The sample mea is: _____ margin of error sample size Log On Ad: Mathway solves algebra homework problems with step-by-step help! Algebra: Probability and statisticsSection SolversSolvers LessonsLessons Answers archiveAnswers
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Click here to see ALL problems on Probability-and-statistics Question 584875: Use the confidence interval to find the margin of error and the sample mean: (0.256,0.380) a.The margin of error is: _____ b.The sample mea is: _____ how to find margin of error on ti 84 Answer by jim_thompson5910(34025) (Show Source): You can put this solution on YOUR website! a) The margin of error is equal to the radius of the confidence interval or half the width of the confidence interval. Margin of Error: ME = (b-a)/2, where the confidence interval is (a,b) ME = (0.380-0.256)/2 ME = 0.062 So the margin of error is 0.062 ------------------------------------------------------- b) The sample mean is the center of the confidence interval. Note: this is assuming that this is a confidence interval for the true population mean. Sample Mean: xbar = (a+b)/2, for some confidence interval (a,b) xbar = (0.256 + 0.380)/2 xbar = 0.318 So the sample mean is 0.318
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in Statistics Famous Mathematicians and Statisticians Calculators Variance and Standard Deviation Calculator Tdist Calculator Permutation Calculator / Combination use the given confidence interval to find the margin of error calculator Calculator Interquartile Range Calculator Linear Regression Calculator Expected Value Calculator Binomial Distribution Calculator Statistics Blog Calculus Matrices Practically Cheating Statistics Handbook Navigation How to Calculate Margin of Error in http://www.algebra.com/algebra/homework/Probability-and-statistics/Probability-and-statistics.faq.question.584875.html Easy Steps Probability and Statistics > Critical Values, Z-Tables & Hypothesis Testing > How to Calculate Margin of Error Contents (click to skip to that section): What is a Margin of Error? How to Calculate Margin of Error (video) What is a Margin of Error? The margin of error is the range of values below and above the sample statistic http://www.statisticshowto.com/how-to-calculate-margin-of-error/ in a confidence interval. The confidence interval is a way to show what the uncertainty is with a certain statistic (i.e. from a poll or survey). For example, a poll might state that there is a 98% confidence interval of 4.88 and 5.26. That means if the poll is repeated using the same techniques, 98% of the time the true population parameter (parameter vs. statistic) will fall within the interval estimates (i.e. 4.88 and 5.26) 98% of the time. What is a Margin of Error Percentage? A margin of error tells you how many percentage points your results will differ from the real population value. For example, a 95% confidence interval with a 4 percent margin of error means that your statistic will be within 4 percentage points of the real population value 95% of the time. The Margin of Error can be calculated in two ways: Margin of error = Critical value x Standard deviation Margin of error = Critical value x Standard error of the statistic Statistics Aren't Always Right! The idea behind conf
test AP formulas FAQ AP study guides AP calculators Binomial Chi-square f Dist Hypergeometric Multinomial Negative binomial Normal Poisson t Dist Random numbers Probability Bayes rule Combinations/permutations Factorial Event counter Wizard Graphing Scientific Financial Calculator books AP calculator review Statistics AP study guides Probability Survey http://stattrek.com/estimation/margin-of-error.aspx sampling Excel Graphing calculators Book reviews Glossary AP practice exam Problems and solutions Formulas Notation Share with Friends Margin of Error In a confidence interval, the range of values above and below the sample statistic is called the margin http://www.dummies.com/education/math/statistics/how-to-calculate-the-margin-of-error-for-a-sample-mean/ of error. For example, suppose we wanted to know the percentage of adults that exercise daily. We could devise a sample design to ensure that our sample estimate will not differ from the true population value by more than, margin of say, 5 percent (the margin of error) 90 percent of the time (the confidence level). How to Compute the Margin of Error The margin of error can be defined by either of the following equations. Margin of error = Critical value x Standard deviation of the statistic Margin of error = Critical value x Standard error of the statistic If you know the standard deviation of the statistic, use the first equation to compute the margin of error. margin of error Otherwise, use the second equation. Previously, we described how to compute the standard deviation and standard error. How to Find the Critical Value The critical value is a factor used to compute the margin of error. This section describes how to find the critical value, when the sampling distribution of the statistic is normal or nearly normal. The central limit theorem states that the sampling distribution of a statistic will be nearly normal, if the sample size is large enough. As a rough guide, many statisticians say that a sample size of 30 is large enough when the population distribution is bell-shaped. But if the original population is badly skewed, has multiple peaks, and/or has outliers, researchers like the sample size to be even larger. When the sampling distribution is nearly normal, the critical value can be expressed as a t score or as a z score. When the sample size is smaller, the critical value should only be expressed as a t statistic. To find the critical value, follow these steps. Compute alpha (α): α = 1 - (confidence level / 100) Find the critical probability (p*): p* = 1 - α/2 To express the critical value as a z score, find the z score having a cumulative probability equal to the critical probability (p*). To express the critical value as a t statistic, follow these steps. Find the degrees of freedom (DF)
WorkSocial MediaSoftwareProgrammingWeb Design & DevelopmentBusinessCareersComputers Online Courses B2B Solutions Shop for Books San Francisco, CA Brr, it´s cold outside Search Submit Learn more with dummies Enter your email to join our mailing list for FREE content right to your inbox. Easy! Your email Submit RELATED ARTICLES How to Calculate the Margin of Error for a Sample… Statistics Essentials For Dummies Statistics For Dummies, 2nd Edition SPSS Statistics for Dummies, 3rd Edition Statistics II for Dummies Load more EducationMathStatisticsHow to Calculate the Margin of Error for a Sample Mean How to Calculate the Margin of Error for a Sample Mean Related Book Statistics For Dummies, 2nd Edition By Deborah J. Rumsey When a research question asks you to find a statistical sample mean (or average), you need to report a margin of error, or MOE, for the sample mean. The general formula for the margin of error for the sample mean (assuming a certain condition is met -- see below) is is the population standard deviation, n is the sample size, and z* is the appropriate z*-value for your desired level of confidence (which you can find in the following table). z*-Values for Selected (Percentage) Confidence Levels Percentage Confidence z*-Value 80 1.28 90 1.645 95 1.96 98 2.33 99 2.58 Note that these values are taken from the standard normal (Z-) distribution. The area between each z* value and the negative of that z* value is the confidence percentage (approximately). For example, the area between z*=1.28 and z=-1.28 is approximately 0.80. This chart can be expanded to other confidence percentages as well. The chart shows only the confidence percentages most commonly used. Here are the steps for calculating the margin of error for a sample mean: Find the population standard deviation and the sample size, n. The population standard deviation,