product      <- c("Laptop","Smartphone","Tablet","Headphones","Smartwatch","Printer","Keyboard","Monitor")
unit_price   <- c(185000,95000,68000,12500,28000,42000,8500,56000)
units_sold   <- c(35,80,45,160,90,38,210,52)
unit_cost    <- c(150000,76000,52000,6500,19000,33000,4200,43000)
ad_cost      <- c(180000,220000,90000,60000,85000,45000,50000,75000)
orders       <- c(35,78,44,150,88,36,200,50)
returned     <- c(2,5,2,12,6,3,8,2)

product_data <- data.frame(product, unit_price, units_sold, unit_cost,
                           ad_cost, orders, returned)
head(product_data, 5); nrow(product_data); ncol(product_data)
dim(product_data); names(product_data); str(product_data)



product_data$revenue    <- product_data$unit_price * product_data$units_sold
product_data$cogs       <- product_data$unit_cost * product_data$units_sold
product_data$gross      <- product_data$revenue - product_data$cogs
product_data$net_contr  <- product_data$gross - product_data$ad_cost
product_data$margin     <- product_data$net_contr / product_data$revenue * 100
product_data$return_rate<- product_data$returned / product_data$orders * 100
print(product_data)