Interview Questions 221c4s

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Give us a brief overview of your CV. Touch through your educational qualifications, role and reponsibilities in your previous organization, your achievements, why you are looking for a change and why you want to our company? Give us an overview of one of the recent projects you have worked on. Tell us the business problem, the technique you used, what were the challenges, the insights & recommendations and how did it benefited the client? Have you ever handled a difficult client? If yes, tell us more about the experience. Prepare a few analytical puzzles. Solve those puzzle books by Shakuntala devi and George summers. Few common puzzles were on cubes, coins, minimum steps for weighing the defective coin among say 81 coins, the rope and matchstick puzzle, puzzles based on time, speed and distance concepts,and the very popular- 3/4 prisoners and the color of the cap puzzle,etc. Just google a few of these puzzles and understand the logic behind it. Mainly start ups and reputed firms viz. Amazon, Flipkart,etc stress more on puzzles to gauge your lateral thinking. By the way anyone, who has ever prepared for MBA entrance exams like CAT, XAT, GMAT,etc will find this easy. What are the tools you have worked on? How would you rate yourself in SAS in a scale of 1 to 10? How would you import a dataset in SAS without using the import wizard? (Ans. the infile command) While importing data how would you make SAS be aware of the missing values? (Hint: read up on 'Missover' & also what`s 'Truncover'?) Tell me the whole syntax of the infile command? While importing the dataset, how will you specify whether the file is tab delimited or csv (comma separated value)? Of course, you are not using the import wizard. What is the difference between format and informat? What is the role of the input statement in the infile command? Difference between Data step and Procs? What are the various Procs you have used in your career? What does Cards and Datalines statement do? How would you make SAS read a character, numeric and date variable while importing a dataset? What are the 3 windows that you see in a SAS environment? What`s the function of each one of them? How will you convert a character variable to numeric? Name the function. (Hint: Read up on put and input functions) What does 'intnx' function do? Tell me more about substr and intck functions. Tell me what all SAS functions you have worked on. What is an outlier? How do you identify an outlier? What are the standard practices in the industry to treat an outlier? What is Proc univariate? What is the difference between Proc summary and Proc means?

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Have you ever worked on Proc Report? Tell me the syntax and applications of it? What is Proc rank? Difference between merge and append? What is the prerequisite for a data set merge? Tell me two different ways by which you can merge two or more datasets in SAS? Tell me at least 3 ways by which you can append two or more datasets in SAS? What is proc sql? What is a through query? Difference between left , right and inner ? Explain with suitable examples. You have a dataset comprising two columns i.e. customer name and age. I want to arrange this dataset in ascending order of age and don`t want any duplicate entry for a particular customer. How will I do it in one step? (Hint: Read up on proc sort) What happens if I do a dataset merge without sorting the dataset first? Does it throws an error or gives a warning? (Very important Question) How would I do a left or right using data set merge? Give the full syntax. List down a few differences between data set merge and proc sql . Which one is faster-- data set merge or proc sql ? How would you append using proc sql? (Hint: UNION query) How would you append using proc dataset? What is proc append? What is proc merge? (Tricky one :P) Is many to many merge possible using Data set merge in SAS? Have you worked on SAS macros? Give me an example and tell me the whole syntax? How comfortable are you in VBA? Can we connect the SAS environment using VBA? Can you tell me the code for the same? At least a basic idea will suffice. What are pivot tables? What is the limit on number of rows in MS excel 2010? I have my data in a CSV file and want to create pivots tables on this dataset in a separate excel file without opening the master data file (i.e. the CSV). Is this possible? If yes, how? What is PDV in SAS? What is the application of the Retain statement in SAS? Explain the LAG function in SAS. When do you use linear regression? Difference between linear and logistic regression? Explain me step by step approach for linear regression that you took in a particular project? What is R-square? What is VIF? Formula for VIF? Is the R square in VIF same as the R-Square of the linear regression? What do you mean by the term Regression? What is the method used in the backend to solve linear regression ? (Ans. LSE)

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What is the method used in the backend to solve logistic regression ? (Ans. Maximum likelihood) What is the difference between correlation and covariance? What is adjusted R square? What are the different hypothesis testing techniques you have used? What is a t-test? What is ANOVA? What is the difference between Type 1 and Type 2 errors? What are alpha and beta errors? What is p-value? why should we accept variables whose p-value is less than 0.05? Is R square a measure of accuracy in linear regression? Why or why not? Is R square a measure of accuracy in logistic regression? Why or why not? Why should we eliminate correlation among independent variables while model building? Can the dependent variable be categorical in a linear regression? Why not? How to you interpret beta estimates in the case of a linear regression? How to you interpret beta estimates in the case of a logistic regression? What does exp(beta) signifies? Can the dependent variables be continuous in a logistic regression? why not? What is odds ratio? What are the various output parameters based on which you understand the accuracy of the logistic model? What is the c-statistics in a logistic regression output? How is it calculated? What is ROC? What are Gains chart and lift chart? What is percent concordance and percent discordance in a logistic regression output? What are decision trees? What is CHAID? Difference between logistic regression and CHAID? And their applications? Can the independent variables be categorical in a logistic regression? What is params ref coding? While logistic regression we sometimes face issues like complete separation or quasi complete separation of datapoints, how do you tackle these issues? What is cluster analysis? Difference between k-means and hierarchial clustering? What is a dendrogram? What is two step clustering? Syntax of Proc cluster? What is factor analysis? What is principal component analysis? When do we use this? What is the significance of the Scree plot in a principal component analysis? What is Eigen value?

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What is market basket analysis? What is the apriori algorithm? Explain confidence, and lift. (These questions are asked mainly to the experienced ones esp. to the ones who have worked in Retail, Insurance or telecom domains) Have you ever worked on data visualization tools like Tableau, Qlikview,etc. Have you worked on monte carlo simulation? What is market mix modelling? What is time series forecasting? What is exponential smoothening? What is ARIMA? What is LP optimization? Difference between LP and NLP optimization? Have you ever worked on excel solver? What is the technique used by excel solver for solving LP optimization problems? (Ans: dual simplex) In an IT company there is a seat cost for each resources on bench. You are in the senior management and want to minimize cost by optimizing the no. of resources on bench. Frame an optimization problem. What is the objective function, decision variables and the constraints? What is credit risk? What are the parameters that you will consider to detect fraudulent credit card transactions? What is churn w.r.t the telecom sector? Explain the model building process and also tell me what are the different variables you think should be significant in the model? In the context of social media analytics, what is sentiment analysis? Explain with suitable examples.