Title: Confidence Intervals: What to Know for Statistics | Albert.io
Headings: Confidence Intervals: What to Know for AP® Statistics
AP® Statistics
Confidence Intervals: What to Know for AP® Statistics
Introduction
What is a Confidence Interval?
Constructing Confidence Intervals
Critical Value
Steps for finding critical value:
Sample Standard Error
Two-sided confidence interval
One-sided confidence interval
Lower interval
Upper interval
Conclusion
Let’s put everything into practice. Try this Statistics practice question:
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Content: Constructing confidence intervals require using the sample mean (sample statistic) and margin of error. Using 90% confidence intervals, you can say that you are 90% confident that the mean height of all the students in the college will lie within the lower and upper bounds of the confidence interval. What is a Confidence Interval? Image Source: Wikimedia Commons
There is always some uncertainty associated with sample statistic being used to make the estimate of the population parameter. Uncertainties may be due to random sampling error. What is a confidence interval? A confidence interval is used to describe these uncertainties. A confidence level places a lower and an upper bound within which the population parameter will lie within the given confidence level. Example 1
The 95% confidence interval for the average weight of adults of 20-25 years of age in a country is (55 kg, 65 kg).