MS-DS Master of Data science Research & Data Analysis 4

Question 1

A Likert-scale survey question (1–5) measuring satisfaction is best analyzed with which statistical approach?

Accepted Answer

Mann-Whitney U test as a non-parametric alternative

Answer

Ordinal Likert data often violates normality assumptions, making the Mann-Whitney U test a robust non-parametric choice for group comparisons.

Question 2

In a multiple regression model, the variance inflation factor (VIF) is used to detect:

Accepted Answer

Multicollinearity among predictors

Answer

VIF quantifies how much a predictor's variance is inflated due to linear correlations with other predictors in the model.

Question 3

Which sampling method ensures proportional representation of subgroups within the population?

Accepted Answer

Stratified random sampling

Answer

Stratified random sampling divides the population into strata and samples from each proportionally, guaranteeing subgroup representation.

Question 4

A receiver operating characteristic (ROC) curve plots sensitivity against:

Accepted Answer

1 – Specificity (false positive rate)

Answer

The ROC curve plots the true positive rate (sensitivity) on the y-axis against the false positive rate (1 – specificity) on the x-axis across all classification thresholds.

Question 5

In Bayesian inference, the posterior distribution is proportional to:

Accepted Answer

The product of the prior and the likelihood

Answer

Bayes' theorem states posterior ∝ likelihood × prior; the marginal likelihood acts as a normalizing constant.

MS-DS Master of Data science Practice Test

MS-DS Master of Data science Practice Test

MS-DS Master of Data science Research & Data Analysis 4