economies.r

country <- c("Brazil", "Russia", "India", "China")
pop.thousands <- c(202679, 146300, 1275921, 1367820)
economies <- cbind(country, pop.thousands) # add populaton
gdp.millions <- c(2346583, 1860598, 2051228, 10356508)
economies <- cbind(economies, gdp.millions) # add gdp in millions
rownames(economies) <- economies[ ,"country"] # store country name in row names
economies <- economies[, -1] # drop the variable "country"
class(economies) <- "numeric" # change matrix to numeric
economies[, 1] <- economies[, 1] / 1000 # change population units to millions
colnames(economies) <- c("pop.millions", "gdp.millions") # change column names
gdp.per.capita <- economies[, 2] / economies[, 1] # create gdp.per.capita vector
economies <- cbind(economies, gdp.per.capita) # add gdp.per.capita to matrix
print(colMeans(economies))