100+ Junior Data Analyst Interview Questions and Answers

Power BI is a business analytics tool by Microsoft that provides interactive visualizations and business intelligence capabilities.

• Developed by Microsoft

• Allows users to create interactive visualizations and reports

• Integrates with various data sources such as Excel, SQL databases, and cloud services

• Enables data exploration and sharing insights with stakeholders

• Offers features like dashboards, data connections, and data preparation

SQL is a programming language used for managing and manipulating relational databases.

• SQL stands for Structured Query Language

• It is used to communicate with databases to perform tasks such as querying data, updating data, and creating tables

• Common SQL commands include SELECT, INSERT, UPDATE, DELETE

• Example: SELECT * FROM table_name WHERE condition;

The available data types in SQL include numeric, character, date/time, and boolean types.

• Numeric data types include integer, decimal, and floating-point types.

• Character data types include char, varchar, and text types.

• Date/time data types include date, time, datetime, and timestamp types.

• Boolean data type represents true or false values.

Joins are used to combine rows from two or more tables based on related columns.

• INNER JOIN: Returns records that have matching values in both tables.

• LEFT JOIN: Returns all records from the left table and the matched records from the right table.

• RIGHT JOIN: Returns all records from the right table and the matched records from the left table.

• FULL JOIN: Returns all records when there is a match in either left or right table.

• CROSS JOIN: Returns the Cartesian product of the two ta...read more

Stored procedure in SQL is a precompiled collection of SQL statements that can be executed by calling the procedure name.

• Stored procedures help improve performance by reducing network traffic and improving security.

• They can be used to encapsulate complex SQL logic for reuse.

• Parameters can be passed to stored procedures for dynamic execution.

• Stored procedures can also be used for error handling and transaction management.

Natural Language Processing (NLP) is a field of AI that focuses on the interaction between computers and human language.

• NLP involves the ability of computers to understand, interpret, and generate human language.

• It encompasses tasks like text classification, sentiment analysis, machine translation, and speech recognition.

• NLP techniques include tokenization, part-of-speech tagging, named entity recognition, and syntactic parsing.

• Examples of NLP applications include virtual ass...read more

Provide clear instructions and support to partners for submitting assessments.

• Create a step-by-step guide on how to submit assessments

• Offer training sessions or webinars to demonstrate the submission process

• Provide a dedicated support team or help desk for partners to reach out to with any questions or issues

• Regularly communicate deadlines and reminders for assessment submissions

Reports can be categorized into operational, tactical, and strategic reports.

• Operational reports provide day-to-day information on business activities.

• Tactical reports provide information on short-term goals and objectives.

• Strategic reports provide information on long-term goals and objectives.

• Other types of reports include financial reports, performance reports, progress reports, and incident reports.

• Examples of reports include sales reports, inventory reports, budget report...read more

RLS stands for Restless Leg Syndrome, a neurological disorder characterized by an uncontrollable urge to move the legs.

• RLS causes uncomfortable sensations in the legs, often relieved by movement

• Symptoms typically worsen at night and can disrupt sleep

• RLS can be idiopathic or secondary to other conditions like iron deficiency or pregnancy

Cross join produces Cartesian product of two tables, while outer join combines rows from two tables based on a related column.

• Cross join returns all possible combinations of rows from two tables.

• Outer join combines rows from two tables based on a related column, including unmatched rows with NULL values.

• Example: Cross join - SELECT * FROM table1 CROSS JOIN table2

• Example: Outer join - SELECT * FROM table1 LEFT JOIN table2 ON table1.id = table2.id

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

• Syntax: VLOOKUP(lookup_value, table_array, col_index_num, [range_lookup])

• lookup_value is the value to search for in the first column of the table

• table_array is the range of cells that contains the table

• col_index_num is the column number in the table from which to return a value

• range_lookup is an optional argument that specifies whether to find an ...read more

Index and match are used in Excel to look up values in a table based on specific criteria.

• Index and match are used together to perform a vertical lookup in Excel.

• Index returns the value of a cell in a table based on the row and column numbers provided.

• Match is used to find the position of a value in a range of cells.

• Index and match are often used instead of VLOOKUP when dealing with large datasets or when the lookup value is not in the first column of the table.

Yes, I enjoy working with data as it allows me to uncover insights and make informed decisions.

• I find analyzing data to be intellectually stimulating

• I enjoy discovering patterns and trends within datasets

• Working with data helps me make data-driven decisions in my work

• I appreciate the challenge of cleaning and organizing data for analysis

Medra coding is a standardized medical terminology used for reporting adverse events and drug reactions.

• Medra stands for Medical Dictionary for Regulatory Activities.

• It is used by pharmaceutical companies, regulatory agencies, and healthcare professionals.

• It helps in identifying and analyzing adverse events and drug reactions in clinical trials and post-marketing surveillance.

• Medra codes are hierarchical and can be expanded to provide more specific details.

• Example: Medra code...read more

Pharmacovigilance involves several phases including signal detection, data collection, data assessment, risk management, and communication.

• Signal detection: Identifying potential safety issues through various sources such as clinical trials, spontaneous reports, and literature reviews.

• Data collection: Gathering information on adverse drug reactions (ADRs) from healthcare professionals, patients, and regulatory authorities.

• Data assessment: Analyzing and evaluating the collecte...read more

My strengths include strong analytical skills, attention to detail, and the ability to work well under pressure.

• Strong analytical skills - able to analyze data effectively and draw meaningful insights

• Attention to detail - meticulous in reviewing and verifying data to ensure accuracy

• Ability to work well under pressure - can handle tight deadlines and high-pressure situations effectively

New drug invention refers to the discovery and development of a novel medication to treat a specific disease or condition.

• New drug invention involves a rigorous process of research, testing, and approval by regulatory agencies.

• It can take years and millions of dollars to bring a new drug to market.

• Examples of recent new drug inventions include the COVID-19 vaccines and treatments for rare diseases like spinal muscular atrophy.

Phase 4 trial is the post-marketing surveillance phase of drug development.

• Phase 4 trial is conducted after a drug has been approved by regulatory agencies.

• It is also known as post-marketing surveillance phase.

• The aim is to monitor the long-term safety and effectiveness of the drug.

• Phase 4 trials involve a large number of participants and can last for several years.

• Examples of drugs that have undergone phase 4 trials include Lipitor and Viagra.

Clinical research is the study of health and illness in people, involving human participants to test new treatments or interventions.

• Clinical research involves conducting studies with human participants to evaluate the safety and efficacy of new treatments, interventions, or medical devices.

• There are typically four phases of clinical research: Phase 1 (testing for safety), Phase 2 (testing for efficacy), Phase 3 (large-scale testing), and Phase 4 (post-marketing surveillance)...read more

Machine learning is a branch of artificial intelligence that enables computers to learn and make predictions without being explicitly programmed.

• Machine learning is a subset of AI that uses algorithms to analyze and interpret data.

• It involves training a model on a dataset to make predictions or take actions.

• There are different types of machine learning, including supervised, unsupervised, and reinforcement learning.

• Examples of machine learning applications include spam filter...read more

SQL explain is a command used to analyze and optimize the execution plan of a SQL query.

• SQL explain provides information on how the database engine executes a query

• It shows the steps involved in processing the query and the order in which they are executed

• The output of SQL explain helps in identifying potential performance bottlenecks and optimizing the query

• Example: EXPLAIN SELECT * FROM table_name WHERE column_name = 'value';

I have intermediate level SQL skills with experience in writing complex queries and optimizing database performance.

• Proficient in writing SQL queries to retrieve, update, and manipulate data

• Familiar with joins, subqueries, and aggregate functions

• Experience in optimizing queries for better performance

• Knowledge of database normalization and indexing

• Comfortable working with large datasets

• Example: SELECT * FROM table WHERE condition;

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

• Use the RANK() function to assign a unique rank to each row within a partition of a result set.

• You can use the PARTITION BY clause to divide the result set into partitions to rank separately within each partition.

• Example: SELECT column1, column2, RANK() OVER (PARTITION BY column1 ORDER BY column2) AS rank_column FROM table_name;

Types of keys in data analysis include primary keys, foreign keys, and composite keys.

• Primary key uniquely identifies each record in a table (e.g. customer ID)

• Foreign key links two tables together (e.g. customer ID in orders table)

• Composite key consists of multiple columns to uniquely identify a record (e.g. combination of customer ID and order ID)

Dot net is a software framework developed by Microsoft for building Windows applications.

• Dot net provides a common language runtime (CLR) that allows developers to write code in different languages such as C#, VB.NET, and F#.

• It includes a large class library called the .NET Framework Class Library (FCL) that provides a wide range of functionality for developers.

• Dot net also includes tools for developing and debugging applications, such as Visual Studio.

• Examples of application...read more

One-hot encoding is a technique used to convert categorical variables into a numerical format for machine learning algorithms.

• It creates a binary column for each category in the variable, with 1 indicating the presence of the category and 0 indicating absence.

• One-hot encoding is commonly used in machine learning models to handle categorical data such as gender, color, or country.

• For example, if a 'color' variable has categories 'red', 'blue', and 'green', one-hot encoding wou...read more

SQL is used to manage and manipulate relational databases.

• SQL allows us to retrieve data from databases using queries.

• It helps in organizing and managing large amounts of data efficiently.

• SQL is used to create, modify, and delete tables and other database objects.

• It is widely used in business intelligence and data analysis to extract insights from data.

• Examples of popular SQL-based databases include MySQL, Oracle, and Microsoft SQL Server.

Forecasting is the process of making predictions about future trends based on past and present data.

• Forecasting involves analyzing historical data to make informed predictions about future outcomes.

• It helps businesses anticipate demand, plan resources, and make strategic decisions.

• Common methods of forecasting include time series analysis, regression analysis, and machine learning algorithms.

• Examples of forecasting include predicting sales for the next quarter, estimating inv...read more

One business understanding problem is identifying customer churn reasons in a subscription-based service.

• Analyze customer data to identify patterns or trends leading to churn

• Utilize predictive modeling to forecast potential churn

• Implement targeted retention strategies based on findings

• Monitor and track the effectiveness of retention efforts

Use RENAME DATABASE statement to change name of database in SQL.

• Use RENAME DATABASE statement followed by current database name and new database name.

• Make sure to have necessary permissions to rename the database.

• Example: RENAME DATABASE old_database TO new_database;

I am a detail-oriented data analyst with a strong background in statistics and programming.

• Graduated with a degree in Statistics

• Proficient in programming languages such as Python and R

• Experience in data cleaning, analysis, and visualization

• Strong problem-solving skills

• Excellent communication and teamwork abilities

Find the second largest number in an array of strings.

• Convert the array of strings to an array of integers.

• Sort the array in descending order.

• Return the second element in the sorted array.

Joins in SQL are used to combine rows from two or more tables based on a related column between them.

• 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.column = table2.column

One of my weaknesses is that I tend to be overly critical of my own work.

• I often spend too much time reviewing and revising my work to ensure it is perfect

• I can be too hard on myself when I make mistakes

• I am working on finding a balance between striving for excellence and being too self-critical

Adverse events are unexpected or harmful reactions to medical treatments or interventions.

• Adverse events can range from mild to severe and can include side effects of medication, complications from surgery, or reactions to medical devices.

• Adverse events can be caused by errors in medical treatment, patient factors such as allergies or pre-existing conditions, or unknown factors.

• Adverse events are closely monitored in the medical field to improve patient safety and prevent fut...read more

Power BI is a business analytics tool that allows users to visualize and share insights from their data.

• Power BI connects to various data sources to import and transform data.

• Users can create interactive reports and dashboards using a drag-and-drop interface.

• It offers a wide range of visualization options such as charts, graphs, and maps.

• Users can share their reports and dashboards with others, either through the Power BI service or by exporting to other formats.

• Power BI also...read more

Reversing a string in C using pointers and arrays.

• Use a pointer to the beginning of the string and another pointer to the end of the string.

• Swap the characters at the two pointers and move them towards each other until they meet in the middle.

• Repeat the process until the entire string is reversed.

My hobbies include analyzing data from various sources and finding patterns. This interest led me to pursue a career in data analysis.

• I enjoy working with Excel and SQL to manipulate and analyze data

• I like to read articles and books about data analysis and statistics

• I participate in online forums and communities to learn from other data analysts

• I have completed online courses and certifications in data analysis

• I enjoy using data to solve real-world problems and make informed ...read more

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

• Data is raw and unorganized information

• It can be in various forms such as text, numbers, images, audio, video, etc.

• Data can be structured, semi-structured, or unstructured

• It is used to gain insights, make informed decisions, and solve problems

• Examples of data include customer information, sales figures, website traffic, social media posts, etc.

count() and count(*) are SQL functions used to count the number of rows in a table.

• count() counts the number of non-null values in a specific column

• count(*) counts the total number of rows in a table

• Example: SELECT count(column_name) FROM table_name;

• Example: SELECT count(*) FROM table_name;

Data analysis is the process of inspecting, cleaning, transforming, and modeling data to discover useful information, draw conclusions, and support decision-making.

• Data analysis involves examining raw data to find patterns, trends, and insights.

• It includes cleaning and organizing data to ensure accuracy and reliability.

• Statistical methods and tools are used to analyze data and make predictions.

• Data visualization techniques are often used to present findings in a clear and und...read more

Handling partners involves effective communication, collaboration, and building strong relationships.

• Maintain open and clear communication with partners to ensure alignment on goals and expectations.

• Collaborate with partners to leverage each other's strengths and resources for mutual benefit.

• Build strong relationships with partners by being reliable, responsive, and proactive in addressing their needs.

• Establish regular check-ins and feedback sessions to assess progress and ad...read more

Sending proper emails involves clear and concise communication, proper formatting, and professional tone.

• Use a clear and concise subject line that summarizes the content of the email.

• Address the recipient properly with a greeting and their name if possible.

• Keep the email body organized with short paragraphs and bullet points if necessary.

• Use professional language and tone, avoiding slang or abbreviations.

• Proofread the email for spelling and grammar errors before sending.

• Inclu...read more

Data mining involves several basic steps to extract useful information from large datasets.

• Data collection and preparation

• Data exploration and visualization

• Data modeling and algorithm selection

• Model evaluation and validation

• Deployment and maintenance

Python is a popular language for data analysis due to its simplicity, versatility, and powerful libraries.

• Python has a large and active community that constantly develops and updates libraries for data analysis.

• Python is easy to learn and read, making it accessible to beginners.

• Python can handle large datasets and complex data structures efficiently.

• Python integrates well with other languages and tools commonly used in data analysis, such as SQL and Excel.

• Python has a wide ra...read more

Pharmacovigilance is the science and activities related to the detection, assessment, understanding, and prevention of adverse effects or any other drug-related problems.

• Pharmacovigilance involves monitoring the safety of medications post-market approval.

• It includes collecting and analyzing data on adverse drug reactions.

• Pharmacovigilance aims to improve patient safety and minimize risks associated with pharmaceutical products.

• Examples of pharmacovigilance activities include ...read more

Macros are used to automate repetitive tasks in Excel, saving time and reducing errors.

• Automate repetitive tasks in Excel

• Save time by reducing manual work

• Reduce errors by eliminating human input