Hashbrown Systems Interview Questions, Process, and Tips

Dplyr package in R is used for data manipulation. Common functions include filter, select, mutate, summarise, arrange.

• filter() - used to subset rows based on conditions

• select() - used to select specific columns

• mutate() - used to create new columns based on existing columns

• summarise() - used to summarize data

• arrange() - used to reorder rows based on column values

Correlation measures the strength and direction of a linear relationship between two variables, while covariance measures the extent to which two variables change together.

• Correlation is standardized, with values ranging from -1 to 1, while covariance is not standardized.

• Correlation is unitless, making it easier to interpret compared to covariance.

• Correlation is used to determine the strength and direction of the relat...read more

Various methods such as visual inspection, mathematical algorithms, and statistical techniques are used to identify the peak and trough of a signal.

• Visual inspection of the signal waveform to identify the highest point as the peak and the lowest point as the trough.

• Mathematical algorithms like finding the derivative of the signal and locating the points where it equals zero to identify peaks and troughs.

• Statistical tec...read more

Qualitative analysis involves non-numerical data while quantitative analysis involves numerical data. Steps include data collection, data cleaning, data analysis, and interpretation.

• Collect relevant data for analysis

• Clean the data by removing any errors or inconsistencies

• Perform qualitative analysis by categorizing and interpreting non-numerical data

• Perform quantitative analysis by applying statistical methods to numer...read more

WITH clause is used to define a temporary result set, while HAVING clause is used to filter groups in SQL queries.

• WITH clause is used to create a temporary table or view that can be referenced in the main query.

• HAVING clause is used with GROUP BY to filter groups based on specified conditions.

• WITH clause is executed before the main query, while HAVING clause is executed after the main query.

• Example: WITH temp_table AS ...read more