# Create a products data frame
products <- data.frame(id = c(1, 2, 3), name = c("Product A", "Product B", "Product C"), brand = c("Brand X", "Brand Y", "Brand X"))

print(products)
# Create a purchases data frame
purchases <- data.frame(customer_id = c(1, 2, 3), product_id = c(1, 2, 3), quantity = c(2, 1, 3))

print(purchases)

# Add a new column named "brand" to purchases data frame
purchases$brand <- products$brand[products$id %in% purchases$product_id]

# View the purchases data frame
purchases