200+ Data Analyst Interview Questions and Answers for Freshers

Code to calculate number of people in a room at EOD given X enter and Y leave throughout the day.

• Create a variable to keep track of the current number of people in the room

• Increment the variable by X every time someone enters the room

• Decrement the variable by Y every time someone leaves the room

• Return the final value of the variable at the end of the day

• Example: If 10 people enter and 5 leave, there will be 5 people in the room at EOD

Questions related to finance and accounting

• IPO stands for Initial Public Offering, which is the first time a company's stock is offered to the public

• Balance sheet has two sides - assets and liabilities & equity

• Depreciation is the decrease in value of an asset over time due to wear and tear or obsolescence

• Financial statements include income statement, balance sheet, and cash flow statement

SQL is a programming language used for managing relational databases. Joins combine data from multiple tables. Union combines results from multiple queries without duplicates, while Union All includes duplicates.

• SQL is a programming language used for managing relational databases.

• Types of joins include inner join, left join, right join, and full outer join.

• Union combines results from multiple queries without duplicates.

• Union All includes duplicates in the combined result set.

Yes, we can add extra row and pivot table in excel.

• To add a row, select the row below where you want to add the new row and right-click, then select 'Insert'.

• To create a pivot table, select the data range and go to 'Insert' tab, click on 'PivotTable' and follow the prompts.

• To add a new pivot table to an existing one, select a cell in the existing pivot table and go to 'Analyze' tab, click on 'PivotTable' and follow the prompts.

Aadhaar card is a unique identification card issued by the Indian government to residents of India.

• Aadhaar card is a 12-digit unique identification number issued by the Unique Identification Authority of India (UIDAI).

• It serves as proof of identity and address for Indian residents.

• Aadhaar card contains biometric and demographic information of the cardholder, including fingerprints and iris scans.

• It is used for various purposes such as opening bank accounts, getting a SIM card...read more

Answering questions related to data filtering, transferring, joining, and SQL functions for a Data Analyst role.

• To transfer data from one sheet to another, you can use functions like VLOOKUP or INDEX/MATCH in Excel.

• Different types of joins in SQL include INNER JOIN, OUTER JOIN, LEFT JOIN, RIGHT JOIN, and SELF JOIN.

• Syntax for INNER JOIN: SELECT columns FROM table1 INNER JOIN table2 ON table1.column = table2.column;

• Syntax for SUMIFS in Excel: =SUMIFS(sum_range, criteria_range1,...read more

VLOOKUP searches for a value in the first column of a table and returns a corresponding value in the same row. INDEX/MATCH uses two functions to look up a value based on its position in a table.

• VLOOKUP only searches for values in the first column of a table, while INDEX/MATCH can search for values in any column.

• INDEX/MATCH is more flexible and efficient for large datasets.

• VLOOKUP is easier to use for simple lookups with small datasets.

• INDEX/MATCH can handle errors more effect...read more

A list is mutable and can be modified, while a tuple is immutable and cannot be changed. List comprehension is a concise way to create lists.

• List: Mutable, can be modified. Tuple: Immutable, cannot be changed.

• List: Defined with square brackets []. Tuple: Defined with parentheses ().

• List comprehension: Concise way to create lists by iterating over an iterable and applying an expression.

• Example of list comprehension: squares = [x**2 for x in range(10)]

R1RCM is a healthcare revenue cycle management company. The role is for a data analyst position.

• R1RCM specializes in providing revenue cycle management services to healthcare providers.

• The company uses advanced technology and analytics to optimize revenue cycle performance.

• As a data analyst, the role involves analyzing and interpreting healthcare data to identify trends and insights.

• The data analyst will work closely with other teams to develop strategies for improving revenu...read more

The Brexit vote could have both positive and negative effects on the Indian economy.

• Positive effects: Increased trade opportunities with the UK, potential for attracting foreign investments from companies relocating from the UK.

• Negative effects: Uncertainty in global markets leading to volatility in exchange rates, potential decline in exports to the UK.

• Example: Indian IT companies may face challenges due to stricter immigration policies in the UK.

• Example: Indian textile expo...read more

Query to extract details of employees with salary more than 5000000.

• Use SELECT statement to retrieve employee details

• Add WHERE clause to filter employees with salary greater than 5000000

• Example: SELECT * FROM employees WHERE salary > 5000000

It is impossible to accurately determine the number of cups of tea consumed in Delhi for a week without proper data.

• There is no official data available on the exact number of cups of tea consumed in Delhi for a week.

• The number of cups of tea consumed in Delhi for a week varies depending on various factors such as weather, season, and individual preferences.

• It is estimated that Delhi consumes a significant amount of tea due to its cultural and historical significance.

• Factors s...read more

No, regression is used for predicting continuous values, while classification is used for predicting categorical values.

• Regression predicts continuous values, while classification predicts categorical values

• Regression models include linear regression, polynomial regression, etc.

• Classification models include logistic regression, decision trees, etc.

Use a SQL query to find different routes for an airline based on source and destination columns in a table.

• Use a SELECT statement to retrieve the distinct combinations of source and destination.

• Use the DISTINCT keyword to ensure only unique routes are returned.

• Order the results by source and destination for easier analysis.

The interview included questions on machine learning, exploratory data analysis, basics of deep learning, and a puzzle.

• Questions on machine learning

• Questions on exploratory data analysis

• Questions on basics of deep learning

• A puzzle was asked

It would take the man 47 days to come out of the well.

• The man climbs 1m (4m up - 3m down) each day.

• He needs to climb a total of 50m to come out of the well.

• Therefore, it would take him 47 days to climb the remaining 46m (50m - 4m).

Dcount function counts the number of unique values in a dataset. ABS function returns the absolute value of a number. To remove minus sign from an integer in Excel, use a formula like =ABS(A1).

• Dcount function counts unique values in a dataset

• ABS function returns absolute value of a number

• To remove minus sign from an integer in Excel, use formula like =ABS(A1)

Use a distributed system with real-time processing to track 1 million records generated every 5 minutes.

• Implement a distributed system like Apache Kafka or Apache Spark to handle the large volume of data.

• Use real-time processing to ensure that the data is analyzed and tracked as soon as it is generated.

• Consider using cloud-based solutions like AWS or Google Cloud Platform for scalability and cost-effectiveness.

• Implement data validation and error handling to ensure data accura...read more

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

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

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

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

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

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

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

Possible reasons for delay in delivery

• Logistical issues such as traffic or weather

• Inadequate inventory management

• Production delays

• Customs clearance delays

• Incorrect address or contact information

• Technical issues with delivery vehicles or equipment

Use Power BI to connect to SQL database, import dataset, and create visualizations

• Connect Power BI to SQL database

• Import dataset from SQL into Power BI

• Create visualizations using the imported data

I prioritize tasks in a data project by assessing deadlines, importance, dependencies, and impact on overall project goals.

• Identify deadlines for each task and prioritize based on urgency

• Consider the importance of each task in relation to project goals

• Take into account dependencies between tasks and prioritize accordingly

• Assess the potential impact of completing each task on the overall project success

Query to retrieve employee names who joined in last 30 days

• Use the current date and subtract 30 days to get the date 30 days ago

• Join the employee table with the date joined column to filter employees who joined in the last 30 days

Various methods such as visual inspection, mathematical algorithms, and statistical techniques are used to identify the peak and trough of a signal.

• Visual inspection of the signal waveform to identify the highest point as the peak and the lowest point as the trough.

• Mathematical algorithms like finding the derivative of the signal and locating the points where it equals zero to identify peaks and troughs.

• Statistical techniques such as moving average or peak detection algorithm...read more

Star and dimension schema are used in data warehousing to organize data, while window functions in SQL are used for analytical queries.

• Star schema is a type of schema where a central fact table is connected to multiple dimension tables.

• Dimension schema is a type of schema where each dimension is represented by a separate table.

• Window functions in SQL are used to perform calculations across a set of table rows related to the current row.

• Examples of window functions include ROW...read more

The total number of flowers accumulated at the end of the day can be calculated by multiplying the number of people by the number of flowers each person offers.

• Multiply the number of people by 5 to get the total number of flowers accumulated

• For example, if there are 10 people, the total number of flowers accumulated would be 10 * 5 = 50

Optimizing reports with large datasets involves using efficient data processing techniques and visualization tools.

• Use data aggregation to summarize large datasets

• Utilize indexing and proper data structures for faster retrieval

• Implement parallel processing or distributed computing for quicker analysis

• Leverage data visualization tools like Tableau or Power BI for easier interpretation

• Consider using sampling techniques to work with subsets of data for initial analysis

Knn is used for classification, Naive Bayes for text classification, and different ML techniques for various tasks.

• Knn is used for classification problems where the data is labeled and the goal is to predict the label of new, unlabeled data points.

• Naive Bayes is used for text classification problems where the goal is to classify documents into different categories based on their content.

• Different ML techniques are used for various tasks such as regression, clustering, anomaly...read more

I have worked with tools such as Excel, SQL, Python, Tableau, and Power BI.

• Excel

• SQL

• Python

• Tableau

• Power BI

I would analyze sales data by identifying trends, customer behavior, and market opportunities to increase revenue.

• Identify key performance indicators (KPIs) such as average order value, conversion rate, and customer acquisition cost.

• Segment customers based on demographics, purchase history, and behavior to target specific groups with personalized marketing strategies.

• Analyze sales channels to determine which ones are most effective in driving revenue and allocate resources ac...read more

I would handle missing values by imputing them using methods like mean, median, mode, or predictive modeling.

• Identify the extent of missing data in the dataset

• Consider the type of missing values (completely at random, missing at random, or not missing at random)

• Impute missing values using mean, median, mode, predictive modeling, or other statistical methods

• Evaluate the impact of imputation on the dataset's integrity and analysis results

I am proficient in R, Excel, VBA, and Python.

• I have experience in data analysis and visualization using R and Excel.

• I have developed macros and automated tasks using VBA.

• I have worked on data manipulation and machine learning projects using Python.

• I am constantly learning and improving my skills in these languages.

To find the minimum element in a stack in O(1) complexity, we can use an auxiliary stack.

• Create an auxiliary stack to keep track of the minimum element.

• Push the first element of the main stack onto the auxiliary stack.

• For each subsequent element, compare it with the top element of the auxiliary stack.

• If it is smaller, push it onto the auxiliary stack.

• To get the minimum element, simply return the top element of the auxiliary stack.

• When popping elements from the main stack, als...read more

Data Analysts are responsible for collecting, processing, and analyzing data to help organizations make informed decisions.

• Collecting and organizing data from various sources

• Cleaning and processing data to ensure accuracy and reliability

• Analyzing data to identify trends, patterns, and insights

• Creating visualizations and reports to communicate findings

• Providing recommendations based on data analysis

• Collaborating with stakeholders to understand business needs and goals

Payables turnover ratio is a financial metric that measures how quickly a company pays off its suppliers.

• It is calculated by dividing the cost of goods sold by the average accounts payable balance.

• A high ratio indicates that a company is paying off its suppliers quickly, while a low ratio suggests that it is taking longer to pay its bills.

• The ratio can be used to assess a company's liquidity and its ability to manage its cash flow.

• For example, if a company has a cost of goods...read more