Chpt9 flashcard #5 - practice set 1

Front

What is a null hypothesis (H0)?

Back

The null hypothesis (H0) is a statement that there is no effect or no difference, and it serves as the default assumption in hypothesis testing.

Front

What is an alternative hypothesis (H1)?

Back

The alternative hypothesis (H1) is a statement that indicates the presence of an effect or a difference, opposing the null hypothesis.

Front

What does a significance level (alpha) of 0.05 mean?

Back

A significance level of 0.05 indicates a 5% risk of concluding that a difference exists when there is no actual difference.

Front

What is a p-value?

Back

A p-value is the probability of obtaining test results at least as extreme as the observed results, assuming that the null hypothesis is true.

Front

What does it mean to reject the null hypothesis?

Back

Rejecting the null hypothesis means that the evidence suggests a statistically significant effect or difference exists.

Front

What does it mean to fail to reject the null hypothesis?

Back

Failing to reject the null hypothesis means that there is not enough evidence to support the alternative hypothesis.

Front

What is a confidence interval?

Back

A confidence interval is a range of values that is likely to contain the population parameter with a specified level of confidence, typically 95%.

Front

How do you interpret a confidence interval that does not contain zero?

Back

If a confidence interval does not contain zero, it suggests that there is a statistically significant difference between the groups being compared.

Front

What is a paired sample t-test?

Back

A paired sample t-test is a statistical method used to compare two related groups to determine if there is a significant difference in their means.

Front

What is the formula for calculating the test statistic in a t-test?

Back

The test statistic (t) is calculated as: t = (mean difference) / (standard deviation of the differences / sqrt(n)) where n is the number of pairs.