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Introduction

Data Science, as a domain, has seen massive growth in the past few years.  Nearly 2.5 quintillion bytes of data gets generated every day. These data sets, when churned into useful information, play a crucial role in the decision making of a business operation. But how do businesses and firms deal with this massive data that is generated from various sources? They require professionals who have expertise in Data Analysis tools and techniques. 

If you are also looking forward to a career in this domain, then this article on Data Analyst interview questions with answers is definitely a must-read. You will come across some of the most popular questions related to Data Analytics concepts. These common data analytics interview questions will help you gain a competitive understanding of the market.

There are several job roles for experts who know how to culture humongous amounts of data into a logical structure. Data Analysts are among such roles. They work with massive collections of data and gather hidden insights from a business point of view. The process of extracting insights from data is called Data Analysis.  The types of questions mentioned in this article would be best suited for someone who is a fresher and starting a career in Data Science, or someone who has switched their career to data science recently and are planning to appear for Data Analyst interviews for the first time.

We’ve divided these 12 Data Analyst Interview Questions into the following categories:

  1. General Questions
  2. Excel Interview Questions for Data Analyst
  3. Statistics Interview Questions for Data Analyst
  4. SQL Interview Questions for Data Analyst
  5. Python Data Analyst Interview Questions

Data Analysis Interview Questions

Here are some of the most common Data Analyst interview questions and their answers –

1. General Questions

General questions on data analyst

A) What is the responsibility of a data analyst? What frameworks are used by Data Analysts? (Data Analyst technical interview questions)

The responsibilities of a Data Analyst include:

  • Collecting data on the number of sales, logistics, market research, linguistics, or other domains. These can be a primary as well as an auxiliary source of data 
  • Resolving business-related issues for clients and analyzing data for performing an audit on data for better insight
  • Supporting different operations of data analysis as well as coordinating with clients or other members of various departments
  • Filtering and cleansing data

The frameworks used for data analysis are:

  • Hadoop Distributed File System
  • MapReduce
  • ZooKeeper
  • Yet Another Resource Negotiator
  • Flume
  • Spark

B) What do you understand by Data Cleansing? Mention the best ways to practice data cleansing.

Data cleansing is the method of detecting errors and removing inconsistencies from the extracted dataset for improving its quality. 

The best ways of practicing data cleansing are:

  • Arranging or dividing data based on some attribute
  • Segregating large data chunks into smaller datasets for better visibility
  • Gaining a statistical insight for each data column
  • Creating automated utility functions to deal with common cleaning tasks

C) Name some popular tools used for data analysis

  • Tableau
  • NodeXL
  • Google Search Operators
  • Solver
  • KNIME
  • Google Fusion Tables
  • RapidMiner

2. Excel Interview Questions for Data Analyst

Data analyst interview questions

Microsoft Excel is one of several effective data handling systems. It provides some powerful features for managing quantitative analysis, visualizing wide datasets, as well as statistical analysis using an automatic interface for data manipulation. It is one of the most common data analysis tools, and frequent excel and advanced excel interview questions are asked during a Data Analyst interview. 

A) What is a waterfall chart? When do we use it? (Excel interview questions for data analyst)

MS Excel’s waterfall chart helps in showing both positive and negative values that show the resultant value. The waterfall chart is useful in situations when you want to visualize the net value of an enterprise. 

B) How can you highlight the negative valued cells in Excel? (Advanced excel interview questions for data analyst)

By using conditional formatting, we can highlight the negative valued cells in Excel. 

The steps are:

  1. Select the cells for highlighting
  2. Under the Home tab, click on Conditional Formatting
  3. Choose the Highlight Cell Rules and then click the “Less Than” option
  4. From the “Less Than” dialogue box, assign the value as zero

C) Is it possible to create a Pivot Table from multiple tables?

Yes, it is possible to make one Pivot Table from various tables when there is an association or connection between these multiple tables.

3. Statistics Interview Questions for Data Analyst

Statistics interview questions for data analyst

Statistics is a significant branch of data analysis as it deals with data collection, data organization, data interpretation, and data presentation. Many data analyst interview questions are from this vertical too.

A) Define the statistical power of sensitivity (Statistics interview questions for data analyst)

The statistical power of sensitivity refers to the test sensitivity of data to a particular measure and is used to prove the accuracy of a classifier. Examples of these classifiers are Logistic Regression, Random Forest, Support Vector Machine (SVM), etc.

B) Define A/B testing

In statistics, A/B testing (also known as split testing) is the hypothesis testing methodology. This method is used for a randomized experiment. Depending on sample statistics, this analytical method can estimate the population parameters.

4. SQL Interview Questions for Data Analyst

SQL Interview Questions for Data Analyst

Data analysts also use Relational Database Management System, as it is the most popular database to date. Hence, a data analyst needs to have good command over SQL. Here are some SQL data analyst interview questions and answers:

A) Which is the default port number for the SQL server? (SQL query interview questions for data analyst)

The default port number (TCP) assigned to the SQL server by the Internet Assigned Number Authority (IANA) is 1433.

B) Define Normalization

Normalization is the method used for organizing data in order to avoid data duplication or data redundancy. Four popular normalization types are – First Normal Form (1NF), Second Normal Form (2NF), Third Normal Form (3NF), and Boyce-Codd Normal Form (BCNF).

5. Python Data Analyst Interview Questions

Python Data Analyst Interview Questions

Python is the most popular language for handling data-related tasks. Python’s readability and simplicity make it easy to learn and use. Let’s take a look at the most common Python data analyst interview questions:

A) Mention the different built-in data types used in Python 

  • Number (float, integer)
  • String
  • Tuple
  • List
  • Set
  • Dictionary

B) Define Lambda Functions in Python 

In Python, Lambda functions are anonymous functions. It is applied to define a function very compact and holds only one expression.

Tips

  • Make sure you know the use of one or two data analysis frameworks.
  • It is essential to know the data extraction formula and data visualization techniques using excel.
  • Understanding and extraction of data cleansing is also an essential skill of data analysts.

Conclusion

The role of a data analyst is very crucial for every organization, and getting a job in this domain will have a very long future growth. With these data analytics interview questions and answers to your aid, we are sure that you can crack your way into the position of becoming a successful data analyst. All the best! If you want to learn more about Data Analytics and Business Analytics in detail, you can check out our “Integrated Program in Business Analytics“, a 10-month program in collaboration with IIM-Indore.

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