Introduction to R Syntax

calculate_annual_growth <- function(year_one,year_two,pop_y1, pop_y2,city) {
  annual_growth <- (((pop_y2 - pop_y1) / pop_y1) * 100) / (year_two-year_one)
  message <- paste("From", year_one, "to", year_two, "the population of", city, "grew by approximately", annual_growth, "% each year.")
  print(message)
  return(annual_growth)
}
# Write your code starting here:
city_name <-"Istanbul, Turkey"
pop_year_one <- 691000
pop_year_two <- 15029231
pop_change <- pop_year_two - pop_year_one
print(pop_change)

## [1] 14338231

percentage_gr = pop_change / pop_year_one * 100
print(percentage_gr)

## [1] 2074.997

annual_gr <- percentage_gr / (2017 - 1927)
print(annual_gr)

## [1] 23.05553

calculate_annual_growth(1927, 2017, pop_year_one, pop_year_two, city_name)

## [1] "From 1927 to 2017 the population of Istanbul, Turkey grew by approximately 23.0555250040199 % each year."

## [1] 23.05553