Data Science Practice Test

1Which Python library is most commonly used for data manipulation and analysis in a DataFrame structure?

NumPy

Pandas

Matplotlib

Scikit-learn

2What is the primary purpose of a 'train-test split' in machine learning?

To make the model run faster during training.

To artificially increase the size of the dataset.

To evaluate the model's generalization performance on unseen data.

To select the most important features for the model.

3In SQL, which clause is used to filter rows based on a specified condition?

WHERE

FILTER

HAVING

CONDITION

4Which type of plot is best suited for visualizing the relationship between two continuous numerical variables?

Bar Chart

Histogram

Box Plot

Scatter Plot

5What does the term 'NaN' typically represent in a Pandas DataFrame?

A string value 'NaN'.

A missing or undefined numerical value.

Zero.

An outlier value.

6Which statistical measure represents the middle value in a sorted dataset?

Median

Mean

Mode

Standard Deviation

7What is the main goal of 'Feature Engineering' in data science?

To reduce the number of rows in the dataset.

To visualize the data more effectively.

To create new, more informative features from existing data to improve model performance.

To choose the best machine learning algorithm.

8Which machine learning task involves predicting a continuous numerical value (e.g., price, temperature)?

Classification

Clustering

Anomaly Detection

Regression

9What Python function is used to display output to the console?

display()

print()

show()

output()

10In Pandas, how would you typically select the first 5 rows of a DataFrame named `df`?

df.head()

df.first(5)

df.top(5)

df[:5]

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