Data Science Data Science MCQ 4

Question 1

What is multicollinearity in a regression model?

Accepted Answer

High correlation among predictor variables

Answer

Correlation between the predictors and the target

Answer

Non-linear relationships in the residuals

Answer

Presence of outliers in the response

Question 2

Which activation function outputs values between 0 and 1 and is often used for binary classification output?

Accepted Answer

Sigmoid

Answer

ReLU

Answer

Tanh

Answer

Softmax

Question 3

What does the bias-variance tradeoff describe?

Accepted Answer

The balance between underfitting and overfitting error sources

Answer

The choice between two optimizers

Answer

The ratio of training to test data

Answer

The split between numeric and categorical features

Question 4

Which SQL clause is used to filter groups after aggregation?

Accepted Answer

HAVING

Answer

WHERE

Answer

GROUP BY

Answer

ORDER BY

Question 5

What is the purpose of a train-validation-test split?

Accepted Answer

To tune hyperparameters and get an unbiased final performance estimate

Answer

To increase the total amount of data

Answer

To balance class proportions

Answer

To remove correlated features

Question 6

Which method imputes missing numerical values using neighboring observations?

Accepted Answer

K-nearest neighbors imputation

Answer

Mode imputation

Answer

One-hot encoding

Answer

Log transformation

Question 7

In time series analysis, what does 'stationarity' mean?

Accepted Answer

Statistical properties like mean and variance stay constant over time

Answer

The series has no missing values

Answer

The data is sorted chronologically

Answer

The series contains only positive values