1000+ Data Analyst Interview Questions and Answers

Increasing income in mushroom cultivation can be achieved through various strategies.

• Diversify mushroom varieties to cater to different market demands

• Improve cultivation techniques to increase yield and reduce costs

• Develop value-added products like mushroom powders or extracts

• Establish direct sales channels to eliminate middlemen and increase profit margins

• Explore export opportunities to reach international markets

• Invest in marketing and branding to create awareness and attra...read more

Hypothesis testing in ticket closing example

• Define null and alternative hypothesis

• Choose appropriate statistical test

• Set significance level

• Collect data and calculate test statistic

• Determine p-value and compare with significance level

• Make conclusion and interpret results

Primary market is where new securities are issued and sold for the first time, while secondary market is where already issued securities are traded among investors.

• Primary market is also known as the new issue market.

• Companies issue securities in the primary market to raise capital.

• Investors buy securities in the primary market directly from the issuer.

• Secondary market is also known as the stock market.

• Investors buy and sell securities in the secondary market among themselves...read more

I have 3 years of experience in Python and 2 years in R.

• 3 years of experience in Python, used for data cleaning, analysis, and visualization.

• 2 years of experience in R, utilized for statistical analysis and data modeling.

• Proficient in using libraries like pandas, numpy, matplotlib in Python and ggplot2, dplyr in R.

Credit and operations concepts in relation to KYC procedures and client data privacy.

• Credit refers to the extension of money or resources to a client based on their financial history and ability to repay.

• Operations involve the day-to-day processes and procedures within a financial institution to ensure smooth functioning.

• KYC procedures are used to verify the identity of clients to prevent fraud and money laundering.

• Privacy of client data is crucial to maintain trust and confi...read more

NLP stands for Natural Language Processing and GDF Function is a tool used for data analysis.

• NLP is a branch of AI that deals with the interaction between computers and humans using natural language.

• It involves tasks such as sentiment analysis, language translation, and speech recognition.

• GDF Function is a tool used in data analysis to create graphs and charts to visualize data.

• It stands for Graph Definition File and is used in software such as Gephi and SigmaJS.

• GDF Function ...read more

Asking for clarification shows engagement and interest in the conversation.

• Asking for clarification demonstrates active listening and a desire to fully understand the topic.

• It can also help clarify any misunderstandings or uncertainties, leading to more productive discussions.

• Examples: 'Could you please explain that concept in more detail?' or 'I'm not sure I understand, could you provide an example?'

I don't have the available data to answer the question.

Using a balance scale, find the lighter coin among 9 identical coins with only 2 weighings.

• Divide the coins into 3 groups of 3 coins each.

• Weigh any 2 groups against each other.

• If the scales balance, the lighter coin is in the third group.

• If the scales do not balance, the lighter coin is in the lighter group.

• Divide the lighter group into 3 individual coins and weigh any 2 of them against each other.

• If the scales balance, the lighter coin is the one that was not weighed.

• If the ...read more

Python code to retrieve common rows from two tables

• Use pandas library to read tables and perform operations

• Merge the two tables using a common column

• Filter the merged table to get common rows

Formula is a mathematical expression while function is a pre-built formula that performs a specific task.

• Formula is a combination of mathematical operators and values used to calculate a result.

• Function is a pre-built formula that performs a specific task, such as finding the average of a range of numbers.

• Formulas can be customized and modified, while functions are fixed and cannot be changed.

• Examples of functions include SUM, AVERAGE, MAX, MIN, etc.

Lack of proper knowledge, poor cultivation practices, and inadequate environmental conditions can lower person to standard person in mushroom cultivation.

• Lack of knowledge about different mushroom species and their specific cultivation requirements

• Poor cultivation practices such as improper substrate preparation, inadequate sterilization, or incorrect temperature and humidity control

• Inadequate environmental conditions like insufficient light, improper ventilation, or contamin...read more

Find a string matching a specific pattern in a list of strings.

• Use regular expressions to search for the pattern in each string.

• Iterate through the list of strings and apply the pattern matching logic.

• Return the string that matches the pattern, if found.

• Example: List of strings - ['apple', 'banana', 'cherry'], pattern - 'ba' would return 'banana'.

Create calculated fields in Tableau to dynamically adjust to changing table columns.

• Use calculated fields to reference specific columns by name instead of position.

• Utilize parameters to allow users to select which columns to display.

• Consider using custom SQL queries to dynamically adjust to changing table structure.

The requirement of bananas in a city like Mumbai can be calculated based on population, consumption habits, and availability.

• Calculate the population of Mumbai

• Estimate the average consumption of bananas per person

• Consider factors like tourism and events that may increase demand

• Take into account the availability of bananas from local markets and imports

A good retailer focuses on customer satisfaction, product quality, and efficient operations.

• Good retailers prioritize customer satisfaction by providing excellent customer service and addressing customer needs.

• Good retailers offer high-quality products that meet customer expectations.

• Good retailers have efficient operations, including inventory management, supply chain logistics, and streamlined processes.

• Bad retailers may have poor customer service, low-quality products, and...read more

Yes, but it requires careful handling of data types and potential conversion.

• Union can be performed on tables with different datatypes, but the resulting table will have a common datatype for each column.

• Data types should be compatible, otherwise conversion may be necessary.

• For example, a table with a column of integers can be unioned with a table with a column of floats, but the resulting column will be of type float.

• Careful attention should be paid to ensure that the result...read more

The order of execution of an SQL query involves multiple steps to retrieve data from a database.

• 1. Parsing: The SQL query is first parsed to check for syntax errors.

• 2. Optimization: The query optimizer creates an execution plan to determine the most efficient way to retrieve data.

• 3. Compilation: The optimized query is compiled into an executable form.

• 4. Execution: The compiled query is executed by the database engine to retrieve the requested data.

• 5. Fetching: The retrieved d...read more

Skills needed for data analyst include strong analytical skills, proficiency in data analysis tools, programming knowledge, and communication skills.

• Strong analytical skills to interpret complex data sets

• Proficiency in data analysis tools such as Excel, SQL, Python, R, etc.

• Programming knowledge to manipulate and analyze data effectively

• Communication skills to present findings and insights to stakeholders

A trigger in SQL is a set of instructions that automatically executes in response to a specific event or action.

• Triggers can be used to enforce business rules, audit changes, or replicate data.

• They can be defined to execute before or after an INSERT, UPDATE, or DELETE statement.

• Triggers can also be nested, meaning one trigger can execute another trigger.

• Examples of triggers include sending an email notification when a new record is inserted, or updating a summary table when a...read more

To find top performing products on Amazon, look at parameters such as sales rank, customer reviews, ratings, and price.

• Check the sales rank of the product - lower rank indicates higher sales performance

• Look at customer reviews and ratings - higher ratings and positive reviews indicate customer satisfaction

• Consider the price of the product - competitive pricing can attract more customers

• Monitor trends and seasonality - products that are in demand during specific times can perf...read more

Different types of joins in SQL include inner join, left join, right join, and full outer join.

• Inner join: Returns rows when there is a match in both tables.

• Left join: Returns all rows from the left table and the matched rows from the right table.

• Right join: Returns all rows from the right table and the matched rows from the left table.

• Full outer join: Returns rows when there is a match in either table.

Use a subquery to find the highest number that appears only once in a column

• Use a subquery to filter out numbers that appear more than once

• Order the results in descending order and select the top 1

Qualitative analysis involves non-numerical data while quantitative analysis involves numerical data. Steps include data collection, data cleaning, data analysis, and interpretation.

• Collect relevant data for analysis

• Clean the data by removing any errors or inconsistencies

• Perform qualitative analysis by categorizing and interpreting non-numerical data

• Perform quantitative analysis by applying statistical methods to numerical data

• Interpret the results and draw conclusions

The importance of data-driven decision making

• Data-driven decision making is crucial for businesses to stay competitive

• It involves collecting and analyzing data to make informed decisions

• Examples include using customer data to improve marketing strategies or analyzing financial data to make investment decisions

• Data-driven decision making can lead to increased efficiency, cost savings, and better outcomes

• However, it's important to ensure the data being used is accurate and rele...read more

Shares represent ownership in a company, while debentures are a form of loan taken by a company.

• Shares represent ownership in a company, entitling the shareholder to a portion of the company's profits and voting rights.

• Debentures are a form of loan taken by a company, where the company agrees to repay the principal amount along with interest at a specified date.

• Shares are considered equity investments, while debentures are considered debt investments.

• Shareholders have ownersh...read more

Tensors are multi-dimensional arrays used to represent data in the field of data analysis and machine learning.

• Tensors are important in data structures as they can efficiently store and manipulate large amounts of data.

• They are used in various data analysis tasks such as image recognition, natural language processing, and time series analysis.

• Tensors allow for efficient computation and manipulation of multi-dimensional data, enabling complex mathematical operations.

• In machine...read more

To manipulate datasets in Python, steps include loading data, cleaning data, transforming data, and analyzing data using libraries like Pandas.

• Load the dataset using Pandas library

• Clean the data by handling missing values, removing duplicates, and correcting data types

• Transform the data by applying functions, merging datasets, and creating new columns

• Analyze the data by performing statistical analysis, visualizations, and machine learning models

Stored procedures are precompiled SQL queries stored in a database for reuse.

• Stored procedures are precompiled SQL queries stored in a database for reuse

• They can improve performance by reducing network traffic and increasing security

• Stored procedures can be used to encapsulate business logic and complex queries

• Examples include procedures for updating customer information or calculating sales totals

Create a list of even and odd numbers and print them separately.

• Create an empty list to store even numbers

• Create another empty list to store odd numbers

• Iterate through a range of numbers and append them to the respective lists based on their parity

• Print the lists of even and odd numbers separately

Data analysis is crucial for making informed decisions. Tokopedia's vast data provides a great opportunity for analysis. My bachelor's thesis focused on data-driven insights.

• Data allows for informed decision-making and insights.

• Tokopedia's extensive data provides a valuable opportunity for analysis.

• My bachelor's thesis delved into data-driven insights and analysis.

OOPS stands for Object-Oriented Programming. The 4 pillars of OOPS are Inheritance, Encapsulation, Abstraction, and Polymorphism.

• OOPS stands for Object-Oriented Programming

• 4 pillars of OOPS are Inheritance, Encapsulation, Abstraction, and Polymorphism

• Polymorphism allows objects of different classes to be treated as objects of a common superclass

• Example: Sorting an array of strings in ascending order - ['apple', 'banana', 'cherry']

• Example: Sorting an array of strings in descen...read more

I would clarify if the number is in dollars, units, or any other currency.

• Ask for clarification on the unit of the number (e.g. dollars, units, etc.)

• Understand the context in which the number is being provided

• Determine the purpose or reason for providing the number

Natural Language Processing is a field of study that focuses on making computers understand human language.

• It involves using algorithms and statistical models to analyze and interpret human language.

• NLP is used in various applications such as chatbots, sentiment analysis, and language translation.

• Examples of NLP tools include NLTK, spaCy, and Stanford CoreNLP.

Rank function assigns unique rank to each distinct row, while Dense rank function assigns same rank to rows with same values.

• Rank function is used to assign a unique rank to each distinct row based on the order specified in the ORDER BY clause.

• Dense rank function is used to assign the same rank to rows with the same values, skipping the next rank if there are ties.

• Rank function returns consecutive ranks, while dense rank function returns consecutive ranks with no gaps.

• Rank fu...read more

EPS stands for Earnings Per Share. Balance sheet always matches due to the fundamental accounting equation.

• EPS is a financial metric that measures the profit earned by a company per outstanding share of common stock.

• It is calculated by dividing the net income of the company by the total number of outstanding shares.

• Balance sheet always matches because of the fundamental accounting equation which states that assets must always equal liabilities plus equity.

• This means that ever...read more

I chose data analytics as a career because of my passion for solving complex problems using data-driven insights.

• I have always been interested in data analysis and statistics

• I enjoy working with large datasets and finding patterns and trends

• I believe that data analytics can help businesses make better decisions and improve their performance

• I have experience in using various data analysis tools and techniques such as SQL, Python, and Tableau

• I am excited about the potential of ...read more

Code to find duplicate records

• Identify the key columns to check for duplicates

• Use GROUP BY and HAVING clauses to filter out duplicates

• Consider using window functions like ROW_NUMBER() to identify and remove duplicates

• Use programming languages like SQL, Python, or R to write the code

Comparing graphs to real world scenarios

• Graph A represents the sales growth of a company over time

• Graph B shows the population growth of a city over the years

• Graph C depicts the temperature fluctuations throughout a day

• Graph D illustrates the stock market performance of a specific company

Foreign key is a field in a table that refers to the primary key of another table.

• Primary key uniquely identifies a record in a table, while foreign key establishes a link between two tables.

• Primary key cannot have duplicate values, while foreign key can have duplicate values.

• Primary key is used to enforce entity integrity, while foreign key is used to enforce referential integrity.

• Foreign key helps in establishing relationships between tables and maintaining data integrity.

• E...read more

Unwanted safety effect refers to an adverse event or side effect caused by a medication or medical intervention.

• It is an unintended consequence of a medical treatment or intervention

• It can range from mild to severe and can occur immediately or after a period of time

• Examples include allergic reactions, organ damage, and infections

• It is important to monitor and report any unwanted safety effects to ensure patient safety

Python is a high-level programming language known for its simplicity and readability.

• Python is an interpreted language, meaning it does not need to be compiled before running.

• It supports multiple programming paradigms, including object-oriented, imperative, and functional programming.

• Python has a large standard library and a thriving community, making it versatile and widely used.

• Example: Python is used for web development (Django, Flask), data analysis (Pandas, NumPy), and a...read more

Joins combine data from two or more tables based on a related column.

• Joins are used to retrieve data from multiple tables based on a related column

• Common types of joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN

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

Regularly monitor data sources and update pipeline accordingly.

• Set up alerts to notify when changes occur in data sources

• Regularly check data sources for changes

• Update pipeline code to handle changes in data sources

• Test pipeline thoroughly after making changes

• Document changes made to pipeline for future reference

I am highly proficient in using spreadsheet programs to compile and organize data.

• I have used spreadsheet programs extensively to compile and organize data in past positions.

• For example, I have used Excel to analyze sales data and create reports for management.

• I have also used Google Sheets to track project progress and budget expenses.

• In one position, I used spreadsheets to analyze customer feedback and identify trends for product improvement.

• I have experience with functions...read more

Window functions like lag and lead are used to analyze data over a specific range or window.

• Lag function can be used to calculate the difference between current and previous values in a time series data.

• Lead function can be used to calculate the difference between current and future values in a time series data.

• Window functions can be used to calculate moving averages, cumulative sums, and other statistical measures.

• For example, in finance, lag function can be used to calcula...read more

SQL joins are used to combine data from two or more tables based on a related column.

• Inner join returns only the matching rows from both tables

• Left join returns all rows from the left table and matching rows from the right table

• Right join returns all rows from the right table and matching rows from the left table

• Full outer join returns all rows from both tables

• Cross join returns the Cartesian product of both tables