1. Confidence Intervals
Accelerated Math 3

2. Confidence Interval
Two Parts -
An interval calculated from the data, usually of the form:
estimate + margin of error
Gives the probability that the interval will capture the true parameter value in repeated samples.

3. What does that mean?
The purpose of a confidence interval is to say with some degree of certainty that the MEAN for a particular population lies within the range of numbers given.
i.e.: I am 95% confident that the mean age of the students at Georgia Tech is between years old
Higher the confidence, the less accurate! 

4. What does that mean?
Confidence intervals are used when we can only collect a sample of data from a large population.
If we had the data from the entire population we could say EXACTLY what the mean value is with 100% confidence.
If we go to the registrar’s office and find the age of every student at GT and then take the average; we will have the EXACT MEAN.
If we take the age of every person eating in the cafeteria and find the average we will have collected only the mean of a SAMPLE.

5. How do you find the confidence interval?

6. Our only example: #1 from WS!

7. I’m assuming you would like to learn how to do this all in your calculator…again! 