HERE! LEARN, PRACTICE & EXCEL!
Q: What is hypothesis testing? Answer: A procedure to decide between competing claims about
a population parameter.
Q: What is the null hypothesis (H0)? Answer: The claim assumed true until evidence suggests
otherwise.
Q: What is the alternative hypothesis (H1 or Ha)? Answer: The claim we seek evidence for.
Q: What is a test statistic? Answer: A value calculated from sample data used to decide whether
to reject H0.
Q: What is a rejection region? Answer: The set of test statistic values that lead to rejection of
H0.
Q: What is a p-value? Answer: The probability of obtaining a test statistic at least as extreme as
observed, given H0 is true.
Q: What is the decision rule using p-value? Answer: Reject H0 if p-value < α, otherwise fail to
reject H0.
Q: What is a Type I error? Answer: Rejecting H0 when it is true.
Q: What is a Type II error? Answer: Failing to reject H0 when it is false.
Q: What is the significance level α? Answer: The probability of a Type I error.
Q: What is the power of a test? Answer: The probability of correctly rejecting H0 (1 - β).
Q: What is a one-tailed test? Answer: A test where H1 specifies direction (>, <).
Q: What is a two-tailed test? Answer: A test where H1 specifies ≠.
Q: What test is used for population mean when σ is known? Answer: z-test.
Q: What test is used for population mean when σ is unknown? Answer: t-test with n-1 degrees
of freedom.
Q: What test is used to compare two means with equal variances? Answer: Pooled two-sample
t-test.
Q: What test is used to compare two means with unequal variances? Answer: Welch's two-
sample t-test.
APPHIA – Crafted with Care and Precision for Academic Excellence.
1