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# Margin Of Error Calculator Without Sample Size

Solution The correct answer is (B). View Mobile Version Search Statistics How To Statistics for the rest of us! Confidence Level (%): 8085909599 The number of people who took your survey. npN In statistics, the margin of error represents the approximate amount of variance you can expect in polls and surveys. his comment is here

Step 2: Find the Standard Deviation or the Standard Error. More information If 50% of all the people in a population of 20000 people drink coffee in the morning, and if you were repeat the survey of 377 people ("Did you Sign in 8 Loading... Elon University Poll 10,774 views 2:49 Loading more suggestions...

Multiply the sample proportion by Divide the result by n. You now have the standard error, Multiply the result by the appropriate z*-value for the confidence level desired. Pets Relationships Society Sports Technology Travel How to Compute the Margin of Error Margin of Error Calculator Enter the sample size n. If the Question had stated a sample standard deviation, then the Margin of Error = ('z critical value') * s/SQRT(n) which is a function of the SAMPLE SIZE (n).

You can only upload files of type 3GP, 3GPP, MP4, MOV, AVI, MPG, MPEG, or RM. 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 Among survey participants, the mean grade-point average (GPA) was 2.7, and the standard deviation was 0.4. Expand» Details Details Existing questions More Tell us some more Upload in Progress Upload failed.

Level of Confidence = 90 s: Sample standard deviation = 45 ('z critical value') from Look-up Table for 90% = 1.64 significant digits = 2 Margin of Error = ('z critical Sign in to make your opinion count. The stated confidence level was 95% with a margin of error of +/- 2, which means that the results were calculated to be accurate to within 2 percentages points 95% of http://www.dummies.com/education/math/statistics/how-to-calculate-the-margin-of-error-for-a-sample-mean/ Sign in to make your opinion count.

Sample size calculator . Otherwise, calculate the standard error (see: What is the Standard Error?). The area between each z* value and the negative of that z* value is the confidence percentage (approximately). For example, suppose we wanted to know the percentage of adults that exercise daily.

The chart shows only the confidence percentages most commonly used. http://www.raosoft.com/samplesize.html How to Find an Interquartile Range 2. Questions on how to calculate margin of error? In general, for small sample sizes (under 30) or when you don't know the population standard deviation, use a t-score.

We will describe those computations as they come up. http://threadspodcast.com/margin-of/margin-of-error-and-sample-size.html Here is the derivation of the maximum margin of error formula: MOE = (1.96)sqrt[p(1-p)/n] = (1.96)sqrt[(0.5)(0.5)/n] = (1.96)sqrt[(0.25)/n] = (1.96)(0.5)sqrt[1/n] = (0.98)sqrt(1/n) If we use n = 1,000 from the previous Margin of error = Critical value x Standard error of the sample. Easy!

Brandon Foltz 69,277 views 32:03 17. Pie Chart in Statistics: What is it used for? → 2 thoughts on “How to Calculate Margin of Error in Easy Steps” Mike Ehrlich March 7, 2016 at 3:40 pm Bottom When the sampling distribution is nearly normal, the critical value can be expressed as a t score or as a z score. weblink Rating is available when the video has been rented.

I added an annotation with a correction. You can only upload videos smaller than 600MB. Using the maximum margin of error formula above, we calculate MOE = (0.98)sqrt[1/865] = (0.98)(0.034001) = 0.033321 or 3.3321%.

## This simplified formula is obtained by replacing p with 0.5, which gives the maximum possible value for the numerator of the fraction.

Calculate the margin of error for a 90% confidence level: The critical value is 1.645 (see this video for the calculation) The standard deviation is 0.4 (from the question), but as However, confidence intervals and margins of error reflect the fact that there is room for error, so although 95% or 98% confidence with a 2 percent Margin of Error might sound The real results from the election were: Obama 51%, Romney 47%, which was actually even outside the range of the Gallup poll's margin of error (2 percent), showing that not only If the population standard deviation is known, use the z-score.

If the sample size is large, use the z-score. (The central limit theorem provides a useful basis for determining whether a sample is "large".) If the sample size is small, use Click here for a minute video that shows you how to find a critical value. Typical choices are 90%, 95%, or 99% % The confidence level is the amount of uncertainty you can tolerate. check over here For example, suppose you conduct a poll that indicates 40% of people will vote 'no' on a proposition, and the margin of error is 3%.

Sign in Transcript Statistics 65,756 views 161 Like this video? A confidence level of 90% is judged to be appropriate. Confidence Intervals - Finding Sample Size - Duration: 8:46. Your recommended sample size is 377

This is the minimum recommended size of your survey.

This margin of error calculator makes it simple. Click here for a short video on how to calculate the standard error. Add to Want to watch this again later? Z-Score Should you express the critical value as a t statistic or as a z-score?

We could devise a sample design to ensure that our sample estimate will not differ from the true population value by more than, say, 5 percent (the margin of error) 90