Data Analyst Technical Interview Questions and Answers (MCQ): Test Your Knowledge! Which SQL join returns all matching records from both tables and null for non-matches?INNER JOINLEFT JOINRIGHT JOINFULL OUTER JOINHow do you create a dynamic range in Excel?Use OFFSET functionUse VLOOKUPUse Pivot TableUse ChartsWhich SQL function is used to extract a date part from a date?DATEPART()EXTRACT()PART()SPLIT()How does a primary key differ from a unique key?Data typeNull values allowedIndexingUniqueness across tablesWhat is the main purpose of a JOIN in SQL?To combine rows from two or more tablesTo filter dataTo sort dataTo aggregate dataWhat is the purpose of indexing in databases?To improve query performanceTo encrypt dataTo compress dataTo validate dataWhich SQL clause is used to filter groups after aggregation?HAVINGWHEREGROUP BYORDER BYWhich SQL function returns the largest value in a set of values?MAX()LARGEST()TOP()HIGHEST()What is the primary purpose of data masking?To clean dataTo obfuscate sensitive dataTo analyze dataTo visualize dataWhat does the TRIM function do in Excel?Removes extra spacesRemoves leading zerosRemoves trailing zerosRemoves non-numeric charactersWhat is the main principle of the K-Nearest Neighbors algorithm?Maximize distance between clustersMinimize intra-cluster varianceClassify based on closest training examplesReduce dimensionalityWhat type of chart is typically used to display the results of a regression analysis?Pie chartBar chartScatter plotLine chartWhich is NOT a best practice for data visualization?Clear labelingAppropriate chart typeConsistent color schemeOvercrowding with informationWhat is the main goal of data governance?To ensure data is managed as an enterprise assetTo increase data volumeTo improve query performanceTo create more databasesWhat is the purpose of the GROUP BY clause in SQL?To group rows that have the same valuesTo filter rowsTo sort rowsTo join tablesWhat is the primary use of LAG() and LEAD() functions in SQL?To join tablesTo access data from previous or subsequent rowsTo filter rowsTo create indexesWhat is NOT a common application of machine learning in data analysis?Predictive modelingPattern recognitionAnomaly detectionData encryptionWhich chart type is best for showing the changes in a value's ranking over time?Bump chartPie chartBar chartLine chartWhat is the purpose of the AVERAGEIF function in Excel?Averages all cellsConditional averageCalculates meanFinds medianWhat is the main difference between descriptive and inferential statistics?Descriptive summarizes data, inferential makes predictionsThey are the sameDescriptive uses probability, inferential doesn'tInferential summarizes data, descriptive makes predictionsWhich SQL function returns the largest value in a set of values?MAX()TOP()HIGHEST()GREATEST()What is the primary purpose of collaborating with other departments?To avoid workTo understand business needs and contextTo delegate all tasksTo complicate the analysis processWhat is the difference between INNER JOIN and CROSS JOIN in SQL?INNER JOIN returns matching rows, CROSS JOIN returns Cartesian productThey are the same operationINNER JOIN is always fasterCROSS JOIN can only be used with two tablesWhich SQL function returns the length of a string?SIZE()LENGTH()LEN()COUNT()What does CSV stand for in data formats?Comma Separated ValuesComputer Sorted VariablesCalculated Summary ViewCentralized Storage Vector Score: 0/25 Retake Quiz Next Set of Questions