A test has power 0.90 when = 15. True or false: a. The probability of rejecting H0 when = 15 is 0.90. b. The probability of making a correct decision when = 15 is 0.90. c. The probability of making a correct decision when = 15 is 0.10. d. The probability that H0 is true when = 15 is 0.10.

Statistical Reasoning and Practice Week 1 8/31/16 Big Picture: - Data teaches us about the world - There is natural variation in data But if variation is random, we can reduce it by increasing sample size - We then model variation and measure probability and error - We want to use random sampling and assignments to be able to make inferences about the world Basic terms: - Population: the group of people/things of interest - Sample: the subset of the population from which you get data (since you cannot measure an entire population) - Parameter (population parameter): this value summarizes/measures a characteristic of the population - Statistic (sample statistic): this value summarizes/measures a characteristic of the sample data and estimates