Data Science Statistical Concepts and Inference 4

Question 1

In Bayesian inference, the posterior distribution is proportional to:

Accepted Answer

The likelihood times the prior

Answer

Bayes' theorem states the posterior is proportional to the likelihood multiplied by the prior.

Question 2

A prior distribution in Bayesian analysis represents:

Accepted Answer

Beliefs about a parameter before observing data

Answer

The prior encodes existing beliefs or knowledge about a parameter before the current data is seen.

Question 3

Which test is appropriate for comparing the means of two independent groups with continuous outcomes?

Accepted Answer

Independent samples t-test

Answer

An independent samples t-test compares the means of two separate groups.

Question 4

A chi-square test of independence is used to assess:

Accepted Answer

Association between two categorical variables

Answer

The chi-square test of independence evaluates whether two categorical variables are associated.

Question 5

When should ANOVA be preferred over multiple t-tests?

Accepted Answer

When comparing three or more group means while controlling the family-wise error rate

Answer

ANOVA compares three or more means in one test, avoiding the inflated Type I error of many pairwise t-tests.

Data Science Practice Test