Once a statistical experiment yields results, these results have to be qualified. Battery makers only test a sample of their product to estimate how long each battery will last. Confidence intervals are introduced to determine how accurate that estimate is. Does coaching for the Scholastic Aptitude Test make a difference? Significance tests determine whether a correlation between variables is meaningful, or just occurred by chance.
Introduction To Inference
• UNIT 19: SAMPLING DISTRIBUTIONS
• UNIT 20: CONFIDENCE INTERVALS
• UNIT 21: TESTS OF SIGNIFICANCE