DA Data Analysis Tools and Programming

Question 1

Which Python library is primarily used for data manipulation and analysis?

Accepted Answer

Pandas

Answer

Pandas provides the DataFrame structure and a rich set of functions for data cleaning, transformation, and analysis in Python.

Question 2

What does the pandas function df.describe() return?

Accepted Answer

Summary statistics (count, mean, std, min, max, percentiles) for numeric columns

Answer

df.describe() generates descriptive statistics including count, mean, standard deviation, and quartile values for numeric columns.

Question 3

In Excel, which function is used to look up a value in a table and return a corresponding value from another column?

Accepted Answer

VLOOKUP

Answer

VLOOKUP searches the first column of a range for a value and returns a result from a specified column in the same row.

Question 4

What is a pivot table used for in Excel or data analysis?

Accepted Answer

Summarizing, aggregating, and reorganizing data interactively

Answer

Pivot tables let analysts quickly summarize large datasets by grouping and aggregating values across rows and columns.

Question 5

What is R primarily used for in data analysis?

Accepted Answer

Statistical computing and data visualization

Answer

R is a programming language designed for statistical analysis, data manipulation, and producing high-quality visualizations.

DA - Data Analyst Practice Test