Practice Data Analytics Languages Questions and Answers

• Which data validation step is crucial to ensure that all entries in a customer email column are correctly formatted?
• Why is sampling crucial in data analysis, especially when handling large datasets?
• Which of the following best describes the main difference between random and non-random sampling methods?
• Which sampling technique is best suited for dividing a population into distinct subgroups and ensuring each subgroup is proportionally represented?
• Which of the following strategies helps reduce sampling bias?
• What is the purpose of calculating an appropriate sample size in data analysis?
• Which of the following best describes the main purpose of Exploratory Data Analysis (EDA) in data analysis?
• In descriptive statistics, what is the main advantage of using the median over the mean as a measure of central tendency in data analysis?
• Which of the following data visualization tools would be best suited for creating interactive dashboards to track real-time business metrics?
• Which method would be most effective in identifying the relationship strength between two continuous variables?
• In hypothesis testing, which of the following statements best describes the null hypothesis?
• In time series analysis, which component is characterized by predictable, cyclical patterns that repeat at fixed intervals?
• Which of the following forecasting methods is specifically designed to capture both autoregressive and moving average properties, often applied to non-stat...
• When decomposing time series data, which component is primarily targeted to be removed to focus on the longer-term trend?
• Why is testing for stationarity important in time series modeling, and which test is commonly used for this purpose?
• Which of the following scenarios would benefit most from using time series analysis with seasonal decomposition?
• In Excel, when using a Pivot Table to analyze sales data by product and region, which feature allows you to apply different calculations (like average, cou...
• In SQL, which type of join returns all records from the left table and the matched records from the right table, and fills in NULL values for non-matching ...
• In Python, which method in the Pandas library would you use to replace NaN values in a DataFrame with the median value of each column?
• In R, which function from the ggplot2 package would be best suited for creating a scatter plot with different colors representing different categories?
• Which of the following features in Power BI allows for dynamically filtering data across multiple visuals with a single control element?
• A data analyst is tasked with improving operational efficiency by examining employee performance metrics and identifying bottlenecks. Which of the followin...
• In the context of the data analysis process, what is the main purpose of the "modeling" stage?
• When identifying business problems, what is the first step a data analyst should take to ensure clarity and effectiveness in solving the problem?
• Which of the following methods is most commonly used during data wrangling to handle missing values in a dataset?
• What is the main advantage of using data storytelling in presenting data-driven insights?
• Which of the following statements correctly differentiates between continuous and categorical data?
• Which of the following is an example of semi-structured data ?
• What is the difference between samples and populations in data analysis?
• What is the primary difference between Big Data and traditional data ?
• Why is metadata crucial in the management of data?
• Why is sampling commonly used in data analysis, especially when dealing with large datasets?
• Which of the following best differentiates random sampling from non-random sampling techniques?
• Which of the following sampling techniques is most suitable when the population is divided into distinct subgroups, and it is important to ensure each subg...
• Which of the following strategies is most effective in avoiding selection bias when choosing a sample for analysis?
• Which of the following is not a measure of central tendency?
• Which of the following best describes the seasonal component in time series data?
• What is the primary advantage of using the ARIMA (AutoRegressive Integrated Moving Average) model for forecasting time series data?
• Which of the following is the correct decomposition of time series data into its components?
• In the context of time series analysis, the Dickey-Fuller test is used to: