Data and Analytics Machine Learning Fundamentals 2

Question 1

Which algorithm builds an ensemble of decision trees using random subsets of features and training samples?

Accepted Answer

Random Forest

Answer

Gradient Boosting

Answer

Naive Bayes

Answer

K-Nearest Neighbors

Question 2

In a neural network, what is the role of an activation function?

Accepted Answer

To introduce non-linearity so the network can learn complex patterns

Answer

To initialize the weights of the network

Answer

To reduce the number of parameters in the model

Answer

To normalize input data before training

Question 3

What is gradient descent used for in machine learning?

Accepted Answer

Iteratively updating model parameters to minimize the loss function

Answer

Selecting the best features from a dataset

Answer

Splitting data into training and testing sets

Answer

Measuring model performance on unseen data

Question 4

Which type of machine learning is used in recommendation systems where an agent learns by receiving rewards or penalties?

Accepted Answer

Reinforcement learning

Answer

Supervised learning

Answer

Unsupervised learning

Answer

Semi-supervised learning

Question 5

What does PCA (Principal Component Analysis) primarily accomplish in data analysis?

Accepted Answer

Reduces dimensionality by projecting data onto principal components

Answer

Classifies data into predefined categories

Answer

Clusters similar data points together

Answer

Predicts a continuous target variable

Question 6

In logistic regression, what does the output of the sigmoid function represent?

Accepted Answer

The probability that a data point belongs to a particular class

Answer

The exact class label for a data point

Answer

The distance from the decision boundary

Answer

The error rate of the model

Question 7

What is transfer learning in the context of deep learning?

Accepted Answer

Reusing a pre-trained model on a new but related task

Answer

Sending a model from one server to another for inference

Answer

Transferring data between databases for training

Answer

Converting a model from one framework to another