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Data analyst Excel Q2 Can you tell what is a waterfall chart and when do we use it?

Data analyst Excel Q1 Can you make a Pivot Table from multiple tables?

Excel interview QNA

28. Mention the steps of a Data Analysis project.

We discuss this question in question number 9. What are the various steps involved in any data analytics projects…today we will discuss more details.

The core steps of a Data Analysis project include:

· The foremost requirement of a Data Analysis project is an in-depth understanding of the business requirements.

· The second step is to identify the most relevant data sources that best fit the business requirements and obtain the data from reliable and verified sources.

· The third step involves exploring the datasets, cleaning the data, and organizing the same to gain a better understanding of the data at hand.

· In the fourth step, Data Analysts must validate the data.

· The fifth step involves implementing and tracking the datasets.

· The final step is to create a list of the most probable outcomes and iterate until the desired results are accomplished. https://open.spotify.com/show/7nQzL21xSX2Qcjup1FbiYH

https://open.spotify.com/show/7nQzL21xSX2Qcjup1FbiYH

27. How should you tackle multi-source problems?

To tackle multi-source problems, you need to:

· Identify similar data records and combine them into one record that will contain all the useful attributes, minus the redundancy.

· Facilitate schema integration through schema restructuring.

26. Define “Time Series Analysis”.

The sample answer is…

Time Series analysis can usually be performed in two domains – time domain and frequency domain.

Time series analysis is the method where the output forecast of a process is done by analyzing the data collected in the past using techniques like exponential smoothening, log-linear regression method, etc.

25. What is a hash table collision? How can it be prevented?

This is one of the important data analyst interview questions.

The sample answer is…

When two separate keys hash to a common value, a hash table collision occurs. This means that two different data cannot be stored in the same slot.

Hash collisions can be avoided by two methods :

· Separate chaining – In this method, a data structure is used to store multiple items hashing to a common slot.

· Open addressing – This method seeks out empty slots and stores the item in the first empty slot available.

24. What is an N-gram?

An n-gram is a connected sequence of n items in a given text or speech. Precisely, an N-gram is a probabilistic language model used to predict the next item in a particular sequence, as in (n-1).

23. Name the statistical methods that are highly beneficial for data analysts?

The statistical methods that are mostly used by data analysts are:

· Bayesian method

· Markov process

· Simplex algorithm

· Imputation

· Spatial and cluster processes

· Rank statistics, percentile, outliers detection

· Mathematical optimization

22. Define “Collaborative Filtering”.

Collaborative filtering is an algorithm that creates a recommendation system based on the behavioral data of a user. For instance, online shopping sites usually compile a list of items under “recommended for you” based on your browsing history and previous purchases. The crucial components of this algorithm include users, objects, and their interest.