NTT DATA, Inc. Business Analyst Interview Questions and Answers

Autocorrelation is the correlation of a signal with a delayed copy of itself.

• Autocorrelation is used to identify patterns in time series data.

• It is a measure of how similar a signal is to a delayed version of itself.

• Autocorrelation can be positive, negative, or zero.

• It is commonly used in signal processing, finance, and econometrics.

• Autocorrelation can be visualized using a correlogram.

Heteroscedasticity is a statistical term that refers to the unequal variance of a variable across different levels of another variable.

• It is a violation of the assumption of homoscedasticity in regression analysis.

• It can lead to biased and inefficient estimates of regression coefficients.

• It can be detected through residual plots or statistical tests such as the Breusch-Pagan test.

• Examples include income and expenditure...read more

Data analysis is affected by various factors that can influence the accuracy and reliability of the results.

• Data quality: The accuracy, completeness, and consistency of the data can impact the analysis.

• Data sources: The reliability and relevance of the data sources used for analysis can affect the outcomes.

• Data preprocessing: The way data is cleaned, transformed, and prepared for analysis can impact the results.

• Data in...read more