If you are puzzled at the divergent data on air quality and the myriad numbers being thrown around, for those living in and around Delhi, it may be a good idea to get acquainted with the Air Quality Index (AQI) and the numbers behind it since bad air has become an annual fixture.
Under the American system, only PM 2.5 values are taken to determine the level of pollution and the AQI number. Under the American system, values above 500 are considered beyond the AQI.
The US Embassy and Consulates’ air quality monitors measure airborne fine particulate matter (commonly referred to as PM 2.5 because they are less than or equal to 2.5 microns in diameter) on the compounds of the Embassy and Consulates. The caveat is that data from a single monitoring station cannot be applied to an entire city.
The air quality data collected at the US Embassy and Consulates may differ from other monitors located in the same city.
Under the Indian computation, Central Pollution Control Board (CPCB) and Safar India give an index value for AQI which is a numerical scale used for reporting day-to-day air quality with regard to human health and the environment.
The CPCB launched AQI for effective communication of air quality status to people in terms which are easy to understand, and which transforms complex air quality data of various pollutants into a single number (index value), nomenclature and colour.
There are six AQI categories — good, satisfactory, moderately polluted, poor, very poor, and severe.
So, there is a singe AQI number or index value which CPCB puts out or Safar India, another official data source, puts out.
AQ sub-index and health breakpoints are evolved for eight pollutants (PM10, PM2.5, NO2, SO2, CO, O3, NH3, and Pb) for which short-term (up to 24 hours) National Ambient Air Quality Standards are prescribed.
Apart from AQI, there is a count for major pollutants, PM 10 and PM 2.5 which are given separately by these monitoring and forecasting agencies.
In addition, there will be different AQI scores for different locations in a large metropolis like Delhi. For instance, at 5.15 p.m. on Friday, the AQI in Delhi at different locations varied from 450 in Vasant Vihar to a high of 643 in Siri Fort.
The AQI at different localities was mapped at Kalkaji (544), Okhla (553), Tughlakabad (588), Mundka (610), Punjabi Bagh (600) and Anand Vihar (602) — all with varying readings.
With the public health emergency being declared, experts say the announcement could have come earlier.
Tanushree Ganguly, Programme Associate, Council on Energy, Environment and Water said, “Delhi has been experiencing severe air quality conditions for the past four days and PM 2.5 levels have now exceeded 300ug/m3. While declaring a public health emergency today is definitely a welcome move, the announcement could have come earlier”.
She said the authorities must consider lowering the threshold concentration needed for declaring an emergency so that vulnerable sections of the population are not exposed to such high concentrations of PM2.5. “Also, at such high levels of ambient concentration, the indoor air quality also gets worse”. (IANS)
Organizations in all industries rely on raw data to make critical business decisions. The raw data includes sales, social media, inventory, etc. They use this data to develop new products, to enter into new markets, to make investments, and even to target customers. Hence, comes the role of a Data Analyst
It is very difficult to handle the raw data for the organizations so, and there comes the role of a data analyst. Data analyst is the one who collects the data, processes the data, and organizes data into the charts or graphs, or assigns the numerical value for the better understanding and taking important business decisions. With the growing dependency of companies on data analysts, professionals are considering taking data analytics courses to get ahead in this domain.
What does a Data Analyst can do?
Data analysts ascertain how data can be used to answer questions and solve real-life problems. They typically work with the computer system and calculation applications to figure out numbers. Also, they need to have the ability to present the data in interesting ways and explain the actual differences in numbers they make in the future.
Key responsibilities of a Data Analyst
Collecting and interpreting the raw data
Analyzing the results from the interpreted data
Reporting the results in an interesting and understandable way
Identifying patterns and trends in data
Designing, creating and maintaining a database
Defining new data collection and analysis processes
Qualification required for Data Analyst
Degree in mathematics, computer science, statistics, and economics subjects is beneficial in developing a career in data analysis.
Skills required for Data Analyst
Ability to analyze large data
Ability to write comprehensive reports
Strong verbal and non-verbal skills
An analytical and problem-solving mind
Attention to details
How to prepare for the Data Analyst interview
Now comes the question How should I prepare for the role of Data Analyst? And How should I prepare for the interview?
Not every data analyst role is the same in the company, and it may vary in various stages of business growth with a different set of data challenges.
Remember they are hiring you to solve their problems, so go through the company profile for a better understanding of the business they do
What is their business model?
How do they make money?
What are the important metrics to track?
At the time, what might be their data problem?
How are their customers like?
These questions will help you get a clear idea of the company and business they do. This is the first level of preparation for the interview.
Here comes the second level of preparations that are reviewing your skills, it is all about knowing where you fit in these 3 parameters,
Data or number sense and
Good Business Sense
For a Data analyst, it is not just assigning a numerical value to the raw data, but it is to have a piece of knowledge to analyze the business model and should be able to detect the threat.
A good analyst should have a good business sense and technical knowledge in the business world that comes with experience, critical thinking, and plenty of trial & error.
Data or number sense
A data analyst should work with numbers, and there is no escape from numbers in analytics. Numbers serve as a measurable value that supports decision making in a company.
A good analyst should have a good sense of numbers, having the ability to make sense of numbers will let you speak about the company fluctuations and explains a picture of the current situation.
The analyst should know what number to be chosen to make the best sense of data report, and what kind of KPIs should be used to know who the business is doing. And it raises the question to review the calculations and company conversions.
Good Database skills
For a Data analyst, it is a must and should the requirement of having good technical skills and be able to operate different programming languages such as Python, R, SQL, etc.
SQL is a basic database management language you need to focus on, SQL is the ruling language in the analytics world, and it continues to rule.
Last but not least, start attempting practice questions. By doing this, you can take inspiration for yourself and understand what an employer wants to see in you.
It is always suggested to show your interesting projects related to data analysis and exclude mini-projects that you have never really done.
Showcase your degrees that indicates your potential work and interest in the field of data analysis.
A problem-solving approach is very important for data analysts so, it is well and good to practice at least 20 data analysis questions before you go for an interview.
Keep reading various blogs and communities related to data analysis.
Try to attend conferences and meets, which can develop more understanding of data analysis.
Be very creative during your interview.
Internships online coaching is a better way to start your career to data analyst.
Interview question of Data analyst
Here are some interview questions and topics. For better understanding, I have divided it into different sections.
Basic Data Analyst Questions
Here the interviewers ask the fundamental question related to the Data Analyst and its terminologies. For example,
Differentiate Data Mining and Data Analysis?
What is the process of Data Analysis?
Define Data Mining and Data Profiling?
Excel Data Analyst Questions
Excel is the simple software used to do quantitative analysis, statistical analysis with an intuitive interface for data manipulation. They ask a question related to this,
What is a waterfall chart, and when do you use it?
How to highlight negative values cells in Excel?
Statistics Data Analyst Questions
Statistics dealing with data collection and organization, analysis, interpretation, and presentation, the question related to this is,
Define the term Normal Distribution?
What is A/B Testing?
What is the statistical power of sensitivity?
SAS Data Analyst Questions
SAS stands for Statistical Analysis System, which can process complex data and generate meaningful insights that help to make decisions in the business.
What is interleaving in SAS?
Write the basic syntax style of code in SAS?
Explain Do Index, Do While, and the Do Until loop with examples.
SQL Data Analyst Questions
SQL is known as Structured Query Language used to manage data when you do well in SQL questions, as it will be evident in your interviewer that you know how to handle databases.
What is the default port for SQL?
What do you mean by DBMS? What are its different types?
What is ACID property in a database?
Tableau Data Analyst Questions
Tableau is a program for business intelligence that lets anyone connect to the data. It visualizes and creates interactive, shareable dashboards.
Give the difference between Tableau and Power BI?
What is a dual-axis?
What is joining and blending in Tableau?
Puzzle Data Analyst Questions
The analytic industry relies primarily on professionals who specialize in different market-based data analysis methods, but also on those professionals who have outstanding troubleshooting skills. The approach to the problem is an essential skill you need to possess. Oh yes, you should be able to explain to the interviewer your approach as well.
At the end
In this article, we discussed who a data analyst is? What does he do? And responsibilities, qualifications & skills required for the data analyst. We also went through the preparation and tips to crack the data analyst interview.
Now it’s up to you, follow the proper guidelines and keep practicing the things because new data is generated huge, there are various problems in processing this data so, always keep tracking the latest technologies and techniques to solve these problems.