In Excel, an analyst merges the `customers` sheet into the `orders` sheet by matching on `cust_id`, adding the customer type to every order row. Which phase and task?
In Excel, an analyst merges the `customers` sheet into the `orders` sheet by matching on `cust_id`, adding the customer type to every order row. Which phase and task?
Answer
Data preparation — integrate data
Options - A. Data preparation — integrate data - B. Data understanding — collect initial data - C. Modelling — build model - D. Deployment — produce the final report Why - A. Correct — joining two tables on a shared key changes the working table by bringing columns across. That is integration. - B. Collecting is obtaining the source files. Both sheets already exist; this combines them, which is the adjacent phase. - C. The merge answers no question by itself; it prepares the table on which a model will be built. - D. Nothing is handed over. The merge is internal work on the data.