agregar
# aggregate by gender. Note: na.rm = TRUE
#summarize = new column sum
a1 <- data %>% group_by(gndr) %>%
summarise(n_stflife = n(), mean_stflife = mean(stflife, na.rm = TRUE))
a2 <- data %>% group_by(gndr, cntry) %>%
summarise(n_stflife = n(), mean_stflife = mean(stflife, na.rm = TRUE))
Diana H