Data Science Data Science MCQ 3

Question 1

What does a p-value of 0.03 indicate in hypothesis testing at a 0.05 significance level?

Accepted Answer

Reject the null hypothesis

Answer

Since 0.03 is below 0.05, the result is statistically significant and the null is rejected.

Question 2

Which algorithm builds an ensemble of trees sequentially, each correcting the errors of the previous?

Accepted Answer

Gradient boosting

Answer

Gradient boosting adds trees sequentially to minimize the residual errors of prior trees.

Question 3

What is the main advantage of using the F1 score over accuracy?

Accepted Answer

It balances precision and recall, useful for imbalanced classes

Answer

The F1 score is the harmonic mean of precision and recall, helpful when classes are imbalanced.

Question 4

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

Accepted Answer

68%

Answer

By the empirical rule, about 68% of values lie within one standard deviation of the mean.

Question 5

Which preprocessing step scales features to a range typically between 0 and 1?

Accepted Answer

Min-max normalization

Answer

Min-max normalization rescales each feature to a fixed range, usually [0, 1].

Data Science Practice Test