Final Exam Practice Questions (2)

Front

What is the null hypothesis (H0)?

Back

The null hypothesis (H0) is a statement that there is no effect or no difference, and it serves as a default position that indicates no relationship between two measured phenomena.

Front

What does it mean to reject the null hypothesis?

Back

Rejecting the null hypothesis suggests that there is sufficient evidence to support the alternative hypothesis, indicating a significant effect or difference.

Front

What is a chi-square test of independence?

Back

A chi-square test of independence is a statistical test used to determine if there is a significant association between two categorical variables.

Front

What are expected frequencies in a chi-square test?

Back

Expected frequencies are the theoretical frequencies of each category in a contingency table, calculated under the assumption that the null hypothesis is true.

Front

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

Back

The significance level (alpha) is the threshold for determining whether to reject the null hypothesis, commonly set at 0.05.

Front

What is the relationship between sample size and statistical power?

Back

Larger sample sizes generally increase the statistical power of a test, making it more likely to detect a true effect.

Front

What is the mean of a probability distribution?

Back

The mean of a probability distribution is the average value of all possible outcomes, weighted by their probabilities.

Front

What is variance in statistics?

Back

Variance is a measure of how much the values in a dataset differ from the mean, indicating the spread of the data.

Front

What is standard deviation?

Back

Standard deviation is the square root of the variance and provides a measure of the average distance of each data point from the mean.

Front

What is a significant association in statistics?

Back

A significant association indicates that the relationship between two variables is unlikely to be due to chance, often determined by a p-value less than the significance level.