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What are the advantages of a small confidence interval in statistics?
Wiki User
∙ 16y ago
The smaller the confidence interval, the more certain you are of the answers. Remember confidence level and confidence interval (margin of error) are 2 separate things. So if you are using an industry standard confidence level of 95% and 5% margin of error in a standard statistical table, then you could say, for example, with 95% certainty that 60% of those polled would vote for John McCain. Another way of saying this is even though you did not poll everyone (if you did, it would then become a very expensive census), you can say with a high degree of certainty (95% certainty) that 55% to 65% of those polled will vote for Johnny (sadly).
Wiki User
∙ 16y ago
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What are the advantages and disadvantages of inferential statistics?
One advantage of inferential statistics is that large predictions can be made from small data sets. However, if the sample is not representative of the population then the predictions will be incorrect.
How do you measure Confidence Level?
That is with a confidence interval of approximately 95% the "true mean" is within the interval of [336.10, 353.90] and that the sample mean (which is an estimate of the "true mean") is $350.00. SMALL-SAMPLE CONFIDENCE INTERVAL FOR A POPLATION MEAN, t-DISTRIBUTION 95% Confidence Interval = x-bar +/- (t-critical value) * s/SQRT(n) x-bar = SAMPLE MEAN [350] s = STANDARD DEVIATION [100] n = NUMBER OF SAMPLES [200] n - 1 = 199 df (DEGREES OF FREEDOM) t-critical value = (approx) 1.972 from "look-up Table for "two-sided interval" df = 200 [CLOSED df IN TABLE] 95% Confidence Interval: 350+/- 1.972 *100 / SQRT(200) = [336.10, 353.90] That is with a confidence interval of approximately 95% the "true mean" is within the interval of [336.10, 353.90] and that the sample mean (which is an estimate of the "true mean") is $350.00. c. ANSWER: A random selection of 1537 customers will provide 95% confidence for estimating the mean extended warranty price paid. Why??? CHOOSING THE SAMPLE SIZE n = [(z-critical value * s)/B]^2 z-critical value = 1.96 (associated with 95% confidence level) s = STANDARD DEVIATION [100.00] B = BOUND ON THE ERROR OF ESTIMATION [5.00] n = [(1.96 * 100.00)/5.00]^2 = 1537 (ROUNDED - UP) CONCLUSION: A random selection of 1537 customers will provide 95% confidence for estimating the mean extended warranty price paid.
When should inferential statistics typically be used?
Inferential statistics uses data from a small group to make generalizations or inferences about a larger group of people. Inferential statistics should be used with "inferences".
In statistics what is the word for the group you are interested in learning about?
In statistics, it is called the 'population'. There are two types of populations: finite and infinite. A finite population can simply be counted such as the number of students in a class. An infinite population, on the other hand, cannot be counted or is very difficult to count such as the residents in a city. Statistics is all about infinite populations because we need to make conclusions about the entire population based on observations of a small sample of that population.
Why do we need to understand statistics?
Statistics is the mathematical study of populations. We need statistics in order to know something about a large group of something after only studying a small group of that something. We take a sample of a population and study it, and then we can usually draw conclusions about the rest of the population without also studying each member of the population individually. It helps us to be sure that when we try to generalize about some pattern in the weather, behavior of certain people, or the yield of a chemical reaction, that it is objective mathematics that is doing the calculating and not anecdotal evidence based only on human experience. We generalize about patterns and data every day, we just don't call it statistics when we do. We also count things every day, but we don't call it math when we do. Statistics and Multivariable Calculus are both just refined versions of the skills we already use. Understanding statistics makes you a more objective person and increases your ability to generalize about patterns and populations.
What are the advantages and disadvantages of inferential statistics?
One advantage of inferential statistics is that large predictions can be made from small data sets. However, if the sample is not representative of the population then the predictions will be incorrect.
How do you measure Confidence Level?
That is with a confidence interval of approximately 95% the "true mean" is within the interval of [336.10, 353.90] and that the sample mean (which is an estimate of the "true mean") is $350.00. SMALL-SAMPLE CONFIDENCE INTERVAL FOR A POPLATION MEAN, t-DISTRIBUTION 95% Confidence Interval = x-bar +/- (t-critical value) * s/SQRT(n) x-bar = SAMPLE MEAN [350] s = STANDARD DEVIATION [100] n = NUMBER OF SAMPLES [200] n - 1 = 199 df (DEGREES OF FREEDOM) t-critical value = (approx) 1.972 from "look-up Table for "two-sided interval" df = 200 [CLOSED df IN TABLE] 95% Confidence Interval: 350+/- 1.972 *100 / SQRT(200) = [336.10, 353.90] That is with a confidence interval of approximately 95% the "true mean" is within the interval of [336.10, 353.90] and that the sample mean (which is an estimate of the "true mean") is $350.00. c. ANSWER: A random selection of 1537 customers will provide 95% confidence for estimating the mean extended warranty price paid. Why??? CHOOSING THE SAMPLE SIZE n = [(z-critical value * s)/B]^2 z-critical value = 1.96 (associated with 95% confidence level) s = STANDARD DEVIATION [100.00] B = BOUND ON THE ERROR OF ESTIMATION [5.00] n = [(1.96 * 100.00)/5.00]^2 = 1537 (ROUNDED - UP) CONCLUSION: A random selection of 1537 customers will provide 95% confidence for estimating the mean extended warranty price paid.
What rhymes with interval?
at all, fall, call, small,criminal, seminal, wonderful. Depends how you are pronouncing interval.
Advantages of small scale of production?
advantages of small scale production
How many small words can you make from confidence?
Some words that can be made from the letters 'confidence' are:codcodecoinconconeconfinedefinedendicediedinedondoneededenendfedfeedfencefendfinfindfine confidenceiceiconidifininnionneedNedneonnicenieceninenodenoncenoneodeofononce
Speed measured in an infinately small time interval?
instantaneous speed
Is Statistical evidence the same as truth?
No. Good statistical evidence is very clear about how likely it is to be 'correct'. Data can be delivered with (say) a 95% confidence, or a 99% confidence. In general, the bigger the sample you use, the more likely the answer is to be 'correct'. There is always a small chance that it will not be 'correct'. If your sample is 100% of the population, you can say with 100% confidence that you are presenting the truth. But the whole point of statistics is to avoid the cost of a 100% sample, and to be able to infer what the population would answer without needing to ask all of them. The accuracy of this inference depends on: the sample size, the number of questions asked, the actual phrasing of those questions (are they negative, positive, or neutral?), the reason for the survey in the first place, and the interpretation of the results. Statistics are easily manipulated, especially if the sample size is small, there are few real choices offered, and there is no option for "Comments" or "Other". The old saying "You can prove anything by statistics" is correct.
Discuss the advantages and disadvantages of globalisation to small scale industries in India?
what are the advantages of small scale industries?
What advantages do corporations have over small businesses?
List two advantages that corporation have over a small business
How is probability related to statistics?
Probability is related to statistics in a direct manner. When one is doing a research for statistics, probability has to be used especially in sampling a small region.
Where can new business statistics be found?
You can always find information on most businesses by contacting the Small Business Association. They record statistics on most small businesses and you can email them any questions you may have.
Would a topographic map of the Rocky Mountains have a large or small contour interval Explain?
A map of the Rocky Mountains would have a small contour interval because of the multiple peaks and ridges and the constant increase of elevation.
