STAB22H3 Chapter Notes - Chapter 23: Unimodality, Null Hypothesis, Confidence Interval
38
STAB22H3 Full Course Notes
Verified Note
38 documents
Document Summary
Student"s t and degrees of freedom: a family of distributions indexed by its degrees of freedom. The t-models are unimodal, symmetric, and bell-shaped, but generally have fatter tails and a narrower centre than the normal model. As the df increase, t- distributions approach the normal. When certain assumptions and conditions are met, the standardization sample mean, t= y . When the assumptions and conditions are met, we are ready to find the confidence interval for the population mean, . The criticial value you specify and on the number of degrees of freedom, n-1, which we get from the sample size. depends on the particular confidence level, c, that. Nearly normal condition: the data come from a distribution that is unimodal and symmetric. Confidence interval is about the mean not the individual. 90% of intervals found in this way cover the true value. I am 90% confident that the true mean travel time is between.
