STAT 3005 Lecture Notes - Lecture 8: Confidence Interval, Sampling Distribution, Standard Deviation

• School: Virginia Tech
• Department: Statistics
• Course: STAT 3005
• Professor: H C Tavera

Document Summary

Recall ~ statistical inference provides methods for drawing conclusions about a population from sample data such that: collect data from a representative sample of a given population, make an inference about the population. The sample mean will vary from sample to sample. Confidence level: the overall capture rate if the method is used multiple times. The confidence level can be thought of the (cid:494)success rate(cid:495) for the method. When using the method (cid:1857)(cid:1871)(cid:1872)(cid:1865)(cid:1872)(cid:1857) (cid:1865)(cid:1870)(cid:1859)(cid:1866) (cid:1867)(cid:1858) (cid:1857)(cid:1870)(cid:1870)(cid:1867)(cid:1870), % of these intervals capture the unknown population mean . The sampling distribution of tells us how close to the sample mean. Interpretation: 95% of all possible samples of a given size from this population will result in an interval that captures the unknown parameter. Typically chose confidence levels higher than 90%; 95% is the most common. Goal: high confidence with a small margin of error. High confidence suggests that the method almost always gives correct answers. parameter precisely.