All Flashcards
What is a confidence interval?
A range of plausible values for the true population parameter (e.g., slope).
What is the point estimate for the slope?
The slope of the line of best fit, denoted by b.
What is confidence level?
The percentage of confidence intervals that would contain the true parameter if we took many samples.
Define 'degrees of freedom' in the context of regression.
Degrees of freedom (df) = n - 2, where n is the sample size.
What is standard error of the slope?
A measure of the variability of the sample slope estimates around the true population slope.
What is the formula for a confidence interval for the slope?
b ± t* (SE of b), where b is the sample slope, t* is the t-critical value, and SE of b is the standard error of the slope.
How do you calculate degrees of freedom (df) for a regression t-test?
df = n - 2, where n is the sample size.
What are the differences between the t-score from a computer output table and the t-score needed for calculating a confidence interval?
T-score from table: t-score for the sample | T-score for CI: t-score for desired confidence level and degrees of freedom.