AP Stats - Inference

How can you reduce both Type I and Type II errors?

• Increase the sample size.

• Decrease the sample size.

• Use a one-tailed test.

• Increase the significance level.

What does the null hypothesis (H0) always contain?

• A statement of inequality (≠)

• An equal sign (=)

• A variable (x)

• A probability value (p)

What is a Type II error?

• Failing to reject the null hypothesis when it is false.

• Rejecting the null hypothesis when it is true.

• Accepting the alternative hypothesis when it is false.

• Failing to accept the null hypothesis when it is true.

What is the significance level (alpha) in hypothesis testing?

• The probability of making a Type I error.

• The probability of making a Type II error.

• The threshold for determining statistical significance.

• The level of confidence in the results.

Which of the following is NOT a condition for a t-test?

• np > 10 and n(1-p) > 10.

• The samples must be independent.

• The data should be normally distributed.

• The sample size must be equal.

What is the purpose of a hypothesis test?

• To determine if there is enough evidence to reject the null hypothesis.

• To prove the null hypothesis is true.

• To collect data for future research.

• To summarize the results of an experiment.

What type of statistical procedure results in an estimate of an unknown parameter?

• Confidence Interval

• Hypothesis Test

• Regression Analysis

• Descriptive Statistics

What is the difference between a one-tailed and a two-tailed test?

• A one-tailed test checks for the possibility of the relationship in one direction, while a two-tailed test checks in both directions.

• A one-tailed test can only be used for positive relationships, while a two-tailed test can be used for both positive and negative relationships.

• A one-tailed test is more powerful than a two-tailed test because it focuses on one direction only.

• A one-tailed test requires a larger sample size than a two-tailed test.

What do we do when the P-value is greater than alpha?

• Reject H0.

• Fail to reject H0.

• Accept H0.

• Conclude significance.

What is a confidence interval?

• A method to calculate the mean of a dataset.

• A range of values used to estimate an unknown parameter.

• A statistical test for hypothesis testing.

• A graphical representation of data distribution.