Q: What is a hypothesis test? A: Itโs a statistical method to determine whether thereโs enough evidence to reject a claim (the null hypothesis) about a population parameter.
Q: What is the p-value? A: The probability of getting results at least as extreme as the observed ones, assuming the null hypothesis is true.
Q: What's the difference between z-test and t-test? A: Use z-test when population standard deviation is known; use t-test when itโs unknown and sample size is small (n < 30).
Q: What is a Type I error? A: Rejecting the null hypothesis when it is actually true (false positive).
Q: What is a Type II error? A: Failing to reject the null hypothesis when it is actually false (false negative).
Q: What does the significance level (ฮฑ) mean? A: Itโs the probability of making a Type I error. Common values are 0.05 or 0.01.