RA Statistical Analysis and Interpretation 2

Question 1

A chi-square test of independence is most appropriate when a researcher wants to:

Accepted Answer

Examine the relationship between two categorical variables

Answer

The chi-square test of independence assesses whether two categorical (nominal or ordinal) variables are statistically associated or independent of each other.

Question 2

What is the primary purpose of a one-way ANOVA?

Accepted Answer

To compare means across three or more independent groups simultaneously

Answer

ANOVA (Analysis of Variance) tests whether there are statistically significant differences among the means of three or more independent groups without inflating the Type I error rate.

Question 3

A Pearson correlation coefficient of -0.85 between two variables indicates:

Accepted Answer

A strong negative linear relationship

Answer

A Pearson r close to -1 indicates a strong negative linear relationship, meaning as one variable increases, the other tends to decrease proportionally.

Question 4

What is the key difference between parametric and non-parametric statistical tests?

Accepted Answer

Parametric tests assume the data meets certain distribution assumptions; non-parametric tests do not

Answer

Parametric tests assume the underlying population follows a specific distribution (typically normal), while non-parametric tests make fewer assumptions and are suitable when data violates these assumptions.

Question 5

In research, statistical power refers to:

Accepted Answer

The probability of correctly detecting a true effect when one exists

Answer

Statistical power (1 - β) is the probability that a test will correctly reject a false null hypothesis, meaning it will detect a true effect when it actually exists.

RA - Certified Research Assistant Practice Test

RA - Certified Research Assistant Practice Test

RA Statistical Analysis and Interpretation 2