30+ Associate Data Analyst Interview Questions and Answers

Stored procedures are pre-written SQL codes that can be saved and reused. They are used to improve performance and security.

• Stored procedures are used to reduce network traffic by executing a batch of SQL statements at once.

• They can improve performance by reducing the amount of time spent parsing and optimizing SQL statements.

• Stored procedures can also enhance security by allowing access to only specific parts of the database.

• Examples of stored procedures include creating a n...read more

The finding from the project was that there is a strong correlation between customer satisfaction and repeat purchases.

• The project analyzed customer satisfaction surveys and purchase data

• The data showed that customers who reported high satisfaction scores were more likely to make repeat purchases

• This finding suggests that improving customer satisfaction can lead to increased customer loyalty and revenue

Three things I learned from my Data Science and Analytics course are statistical analysis, data visualization, and machine learning.

• Statistical analysis: Learned how to use statistical methods to analyze data and draw conclusions.

• Data visualization: Learned how to create visual representations of data to better understand patterns and trends.

• Machine learning: Learned how to use algorithms to build predictive models and make data-driven decisions.

SQL query to get the second row from the top.

• Use the LIMIT keyword to limit the number of rows returned.

• Use the OFFSET keyword to skip the first row.

• Order the rows by a column to ensure consistent results.

I have experience with various machine learning models such as linear regression, decision trees, random forests, and neural networks.

• Linear regression is used for predicting continuous outcomes.

• Decision trees are used for classification and regression tasks.

• Random forests are an ensemble method that combines multiple decision trees for improved accuracy.

• Neural networks are used for complex pattern recognition and prediction tasks.

vlookup is a function in Excel used to search for a specific value in a table and return a corresponding value from another column.

• vlookup stands for 'vertical lookup'

• It requires a lookup value, a table array, column index number, and an optional range lookup value

• It can only search for values in the leftmost column of the table array

• It returns the first matching value found, so it may not be accurate if there are duplicates

• It can be slow and inefficient for large datasets

The data process in my project involves data collection, cleaning, analysis, and visualization.

• Data collection involved gathering data from various sources such as surveys, databases, and APIs.

• Data cleaning was done to remove duplicates, missing values, and outliers.

• Data analysis was performed using statistical methods and machine learning algorithms.

• Data visualization was used to present the findings in a clear and concise manner.

• The process was iterative, with each step inf...read more

Multi-threading and multi-tasking are techniques used to improve the performance of a computer system.

• Multi-threading is the ability of a CPU to run multiple threads of execution concurrently.

• Multi-tasking is the ability of an operating system to run multiple applications or processes concurrently.

• Multi-threading is used to improve the performance of a single application by dividing it into smaller threads that can run concurrently.

• Multi-tasking is used to improve the overall...read more

Primary key uniquely identifies a record in a table, while a unique key ensures that all values in a column are distinct.

• Primary key is a column or set of columns that uniquely identifies each row in a table

• Primary key cannot have null values

• A table can have only one primary key

• Unique key is a column or set of columns that ensures that all values in the column(s) are distinct

• Unique key can have null values, but only one null value is allowed

• A table can have multiple unique ke...read more

Query to find rows beginning with a letter in SQL

• Use the LIKE operator with the pattern '[letter]%'

• Replace [letter] with the desired letter

• Enclose the pattern in single quotes

• Example: SELECT * FROM table_name WHERE column_name LIKE 'A%'

DBMS is a software system to manage databases, while RDBMS is a type of DBMS that uses a relational model.

• DBMS stands for Database Management System, while RDBMS stands for Relational Database Management System.

• DBMS can manage any type of database, while RDBMS uses a specific model based on tables, keys, and relationships.

• DBMS is less strict in terms of data integrity, while RDBMS enforces strict rules to ensure data consistency.

• Examples of DBMS include MongoDB and Cassandra,...read more

Oops features are object-oriented programming concepts that help in creating reusable and modular code.

• Encapsulation - bundling data and methods that operate on that data within a single unit

• Inheritance - creating new classes from existing ones, inheriting their properties and methods

• Polymorphism - ability of objects to take on multiple forms or behaviors

• Abstraction - hiding implementation details and showing only the necessary information

A primary key is a unique identifier for a record in a database table.

• Primary key ensures that each record in a table is unique

• It is used to establish relationships between tables

• It cannot contain null values

• Examples include social security numbers, email addresses, and employee IDs

Bar chart is used to compare different categories, while histogram is used to show distribution of continuous data.

• Bar chart has discrete categories on x-axis, while histogram has continuous data on x-axis.

• Bar chart has gaps between bars, while histogram bars are adjacent to each other.

• Bar chart is used for categorical data, while histogram is used for numerical data.

• Example: Bar chart can show sales data for different products, while histogram can show distribution of height...read more

Object oriented programming language is a programming paradigm that uses objects to represent data and methods to manipulate that data.

• Object oriented programming languages include Java, Python, C++, Ruby, and many others.

• Objects are instances of classes, which define the properties and behaviors of the object.

• Encapsulation, inheritance, and polymorphism are key concepts in object oriented programming.

• Example: In Java, a class can be defined to represent a car, with propertie...read more

To find duplicates in Excel, use the conditional formatting feature or the Remove Duplicates tool.

• Select the range of cells where you want to find duplicates

• Go to the 'Home' tab and click on 'Conditional Formatting'

• Select 'Highlight Cells Rules' and then 'Duplicate Values'

• Choose the formatting style and click 'OK'

• Alternatively, go to the 'Data' tab and click on 'Remove Duplicates'

• Select the columns where you want to find duplicates and click 'OK'

I have worked on Tableau, Power BI, and Excel for data visualization.

• Tableau for creating interactive dashboards and visualizations

• Power BI for creating reports and visualizations with real-time data

• Excel for creating basic charts and graphs

Minimum number of chess boards required for a tournament puzzle.

• Each game requires one board

• In each round, half of the players will be eliminated

• The number of players in the first round will determine the number of boards needed

• The formula to calculate the number of boards needed is: ceil(total number of players / 2)

A pivot table is a data summarization tool used in spreadsheet programs to analyze, summarize, and present data.

• Allows users to reorganize and summarize selected columns and rows of data

• Helps in analyzing trends, patterns, and relationships within the data

• Enables users to perform calculations, such as sums, averages, counts, etc., on the summarized data

• Provides a dynamic way to view and manipulate data for better decision-making

• Commonly used in Excel, Google Sheets, and other...read more

Joining two tables in SQL involves using the JOIN keyword and specifying the columns to join on.

• Use the JOIN keyword followed by the name of the second table

• Specify the columns to join on using the ON keyword

• There are different types of joins such as INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL OUTER JOIN

• Example: SELECT * FROM table1 JOIN table2 ON table1.column = table2.column

Query to find duplicates in SQL

• Use GROUP BY clause to group the columns that may have duplicates

• Use HAVING clause to filter the groups that have more than one row

• Use COUNT() function to count the number of rows in each group

Left Join is a type of join operation in SQL that returns all rows from the left table and the matched rows from the right table.

• Left Join combines rows from two tables based on a related column between them.

• It includes all rows from the left table, even if there are no matches in the right table.

• If there are no matches, NULL values are included for columns from the right table.

• Example: SELECT * FROM table1 LEFT JOIN table2 ON table1.id = table2.id;

A virtual function is a function in a base class that is declared using the keyword 'virtual' and can be overridden by a function with the same signature in a derived class.

• Virtual functions allow for dynamic polymorphism in object-oriented programming.

• They are used to achieve runtime polymorphism by allowing a function to be overridden in a derived class.

• Virtual functions are declared in the base class with the 'virtual' keyword and can be overridden in derived classes using...read more

The 25 Horse Problem is a logic puzzle that involves determining the fastest 3 horses out of 25 using minimal races.

• Divide the 25 horses into groups of 5 and race them to determine the fastest horse in each group.

• Then race the fastest horses from each group to determine the top 3 fastest horses overall.

• This approach minimizes the number of races needed to find the top 3 horses.

Excel is a powerful spreadsheet program used for data analysis, calculations, and visualization.

• Excel is part of Microsoft Office suite

• It allows users to organize data, perform calculations, and create charts

• Functions like VLOOKUP, SUMIF, and PivotTables are commonly used for data analysis

• Excel can handle large datasets and automate repetitive tasks with macros

Constructor is a special method that is called when an object is created. DBMS stands for Database Management System.

• Constructor is used to initialize the object's state

• DBMS is a software system that manages and organizes data in a database

• Examples of DBMS include MySQL, Oracle, and Microsoft SQL Server

C++ is a high-level programming language used for developing software applications.

• C++ is an object-oriented language, allowing for the creation of classes and objects.

• It is a powerful language with features like polymorphism, inheritance, and encapsulation.

• C++ is commonly used in developing system software, game development, and high-performance applications.

Data is a collection of facts, figures, or statistics that can be analyzed to gain insights and make informed decisions.

• Data refers to any information that can be stored and processed by a computer

• It can be structured or unstructured, and can come from various sources such as sensors, surveys, or social media

• Examples of data include customer demographics, sales figures, and website traffic

• A string is a sequence of characters, typically used to represent text in programming la...read more

Fibonacci series in Python is a sequence of numbers where each number is the sum of the two preceding ones.

• Use a loop to generate the Fibonacci series.

• Start with two initial numbers (0 and 1) and add them to get the next number in the series.

• Repeat this process to generate the entire series.