Title: Confidence Intervals | What you need to know for your Six Sigma exam.
Headings: Confidence Intervals
Confidence Intervals
Confidence Interval vs Confidence Level
Confidence Interval vs Prediction Interval
Estimating Population Mean and Standard Deviation
Margin of Error
Z Scores
Common confidence intervals and corresponding Z scores
Confidence Interval Question Using Z-Score
Confidence Interval Question Using T-Score
Calculating the Confidence Interval Comparing Two Population Means
Example
Additional Confidence Intervals Videos
Confidence intervals for Variation
Confidence intervals for Proportion
What are the Difference Between Control Limits and Confidence Intervals?
Confidence Interval
Also See:
Other Confidence Intervals Problems
ASQ Six Sigma Black Belt Exam Confidence Intervals Questions
Authors

Content: They tell you about the distribution of data values, whereas confidence intervals tell you about a probable population mean. Estimating Population Mean and Standard Deviation
In most cases, we won’t know the mean and standard deviation for an entire population. However, we can calculate the mean and standard deviation for each of our samples. So we can use the sample figures to estimate those of the whole population. This is what we call a point estimate. Once we find the point estimate, we also need to know how accurate it is. For instance , the Central Limit Theorem says that in a large enough sample group (30 or more), the sample’s mean and standard deviation will be close to those of the population. Margin of Error
Margin of error is the maximum expected difference between the actual population parameter and a sample estimate of the parameter. In other words, it is the range of values above and below sample statistics. Margin of error widely used in surveys tells the degree of uncertainty that the survey results might have.