DSE Basic 2

Question 1

Which measure of central tendency is most resistant to outliers?

Accepted Answer

Median

Answer

The median is resistant to outliers because it depends only on rank order, not actual values.

Question 2

In a normal distribution, approximately what percentage of data falls within one standard deviation of the mean?

Accepted Answer

68%

Answer

The empirical rule states that ~68% of data falls within ±1 standard deviation in a normal distribution.

Question 3

What is the primary purpose of data normalization?

Accepted Answer

Scale features to a common range

Answer

Normalization scales features to a common range (e.g., 0–1) so no single feature dominates due to magnitude.

Question 4

Which Python library is most commonly used for data manipulation and analysis?

Accepted Answer

Pandas

Answer

Pandas provides DataFrames and Series structures purpose-built for data cleaning and analysis.

Question 5

What does 'variance' measure in a dataset?

Accepted Answer

The average squared deviation from the mean

Answer

Variance measures how spread out data points are by averaging their squared deviations from the mean.

DSE - Data Science Practice Test