What is the definition of a p-value?
The probability of obtaining a sample result as extreme or more extreme than observed, assuming the null hypothesis is true.
Define null hypothesis.
A statement that there is no significant difference between specified populations, any observed difference being due to sampling or experimental error.
Define alternative hypothesis.
The hypothesis that sample observations are influenced by some non-random cause.
What is a right-tailed test?
A hypothesis test where the alternative hypothesis includes values greater than the null hypothesis value.
What is a left-tailed test?
A hypothesis test where the alternative hypothesis includes values less than the null hypothesis value.
What is a two-tailed test?
A hypothesis test where the alternative hypothesis includes values that are different from the null hypothesis value (both greater and less).
What is the formula for the test statistic (t-score) in a one-sample t-test?
$t = \frac{\bar{x} - \mu_0}{s/\sqrt{n}}$ where $\bar{x}$ is the sample mean, $\mu_0$ is the hypothesized population mean, s is the sample standard deviation, and n is the sample size.
What is the formula for the test statistic (z-score) in a one-sample proportion z-test?
$z = \frac{\hat{p} - p_0}{\sqrt{\frac{p_0(1-p_0)}{n}}}$ where $\hat{p}$ is the sample proportion, $p_0$ is the hypothesized population proportion, and n is the sample size.
What are the differences between a Type I error and a Type II error?
Type I error: Rejecting a true null hypothesis. | Type II error: Failing to reject a false null hypothesis.
What are the differences between a one-tailed test and a two-tailed test?
One-tailed test: Tests for a difference in one direction. | Two-tailed test: Tests for a difference in either direction.
