Смотрим на boxplot
ggplot(df, aes(x = GROUP, y = BIRTH, fill = GROUP)) + geom_boxplot()

ggplot(df, aes(x = GROUP, y = DEATH, fill = GROUP)) + geom_boxplot()

ggplot(df, aes(x = GROUP, y = INF_DEAH, fill = GROUP)) + geom_boxplot()

ggplot(df, aes(x = GROUP, y = LIFE, fill = GROUP)) + geom_boxplot()

ggplot(df, aes(x = GROUP, y = LIFE_D, fill = GROUP)) + geom_boxplot()

ggplot(df, aes(x = GROUP, y = GNP, fill = GROUP)) + geom_boxplot()

t.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == "ASIA", "GNP"])
##
## Welch Two Sample t-test
##
## data: df[df$GROUP == "AFRICA", "GNP"] and df[df$GROUP == "ASIA", "GNP"]
## t = -0.67923, df = 19.794, p-value = 0.5049
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
## -1.2359961 0.6290938
## sample estimates:
## mean of x mean of y
## 6.198446 6.501898
t.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == "EAST_E", "GNP"])
##
## Welch Two Sample t-test
##
## data: df[df$GROUP == "AFRICA", "GNP"] and df[df$GROUP == "EAST_E", "GNP"]
## t = -4.9822, df = 30.021, p-value = 2.445e-05
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
## -1.8068595 -0.7562415
## sample estimates:
## mean of x mean of y
## 6.198446 7.479997
t.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == "MID_EAST", "GNP"])
##
## Welch Two Sample t-test
##
## data: df[df$GROUP == "AFRICA", "GNP"] and df[df$GROUP == "MID_EAST", "GNP"]
## t = -6.5165, df = 17.767, p-value = 4.246e-06
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
## -3.09882 -1.58677
## sample estimates:
## mean of x mean of y
## 6.198446 8.541241
t.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == "SOU_A", "GNP"])
##
## Welch Two Sample t-test
##
## data: df[df$GROUP == "AFRICA", "GNP"] and df[df$GROUP == "SOU_A", "GNP"]
## t = -3.8197, df = 32.155, p-value = 0.0005763
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
## -1.6236709 -0.4943938
## sample estimates:
## mean of x mean of y
## 6.198446 7.257479
#t.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == "WEST_E_A", "GNP"])
wilcox.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == "ASIA", "GNP"])
## Warning in wilcox.test.default(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == :
## cannot compute exact p-value with ties
##
## Wilcoxon rank sum test with continuity correction
##
## data: df[df$GROUP == "AFRICA", "GNP"] and df[df$GROUP == "ASIA", "GNP"]
## W = 184.5, p-value = 0.9124
## alternative hypothesis: true location shift is not equal to 0
wilcox.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == "EAST_E", "GNP"])
## Warning in wilcox.test.default(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == :
## cannot compute exact p-value with ties
##
## Wilcoxon rank sum test with continuity correction
##
## data: df[df$GROUP == "AFRICA", "GNP"] and df[df$GROUP == "EAST_E", "GNP"]
## W = 34.5, p-value = 0.001573
## alternative hypothesis: true location shift is not equal to 0
wilcox.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == "MID_EAST", "GNP"])
## Warning in wilcox.test.default(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == :
## cannot compute exact p-value with ties
##
## Wilcoxon rank sum test with continuity correction
##
## data: df[df$GROUP == "AFRICA", "GNP"] and df[df$GROUP == "MID_EAST", "GNP"]
## W = 13, p-value = 3.239e-05
## alternative hypothesis: true location shift is not equal to 0
wilcox.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == 'SOU_A', "GNP"])
## Warning in wilcox.test.default(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == :
## cannot compute exact p-value with ties
##
## Wilcoxon rank sum test with continuity correction
##
## data: df[df$GROUP == "AFRICA", "GNP"] and df[df$GROUP == "SOU_A", "GNP"]
## W = 61, p-value = 0.002223
## alternative hypothesis: true location shift is not equal to 0
wilcox.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == "WEST_E_A", "GNP"])
## Warning in wilcox.test.default(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == :
## cannot compute exact p-value with ties
##
## Wilcoxon rank sum test with continuity correction
##
## data: df[df$GROUP == "AFRICA", "GNP"] and df[df$GROUP == "WEST_E_A", "GNP"]
## W = 0, p-value = 1.922e-08
## alternative hypothesis: true location shift is not equal to 0
ks.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == "ASIA", "GNP"])
## Warning in ks.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == "ASIA", :
## cannot compute exact p-value with ties
##
## Two-sample Kolmogorov-Smirnov test
##
## data: df[df$GROUP == "AFRICA", "GNP"] and df[df$GROUP == "ASIA", "GNP"]
## D = 0.14286, p-value = 0.9918
## alternative hypothesis: two-sided
ks.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == "EAST_E", "GNP"])
## Warning in ks.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == "EAST_E", :
## cannot compute exact p-value with ties
##
## Two-sample Kolmogorov-Smirnov test
##
## data: df[df$GROUP == "AFRICA", "GNP"] and df[df$GROUP == "EAST_E", "GNP"]
## D = 0.7037, p-value = 0.002499
## alternative hypothesis: two-sided
ks.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == "MID_EAST", "GNP"])
## Warning in ks.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == "MID_EAST", :
## cannot compute exact p-value with ties
##
## Two-sample Kolmogorov-Smirnov test
##
## data: df[df$GROUP == "AFRICA", "GNP"] and df[df$GROUP == "MID_EAST", "GNP"]
## D = 0.81481, p-value = 0.0001238
## alternative hypothesis: two-sided
ks.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == "SOU_A", "GNP"])
## Warning in ks.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == "SOU_A", :
## cannot compute exact p-value with ties
##
## Two-sample Kolmogorov-Smirnov test
##
## data: df[df$GROUP == "AFRICA", "GNP"] and df[df$GROUP == "SOU_A", "GNP"]
## D = 0.57407, p-value = 0.008374
## alternative hypothesis: two-sided
ks.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == "WEST_E_A", "GNP"])
## Warning in ks.test(df[df$GROUP == "AFRICA", "GNP"], df[df$GROUP == "WEST_E_A", :
## cannot compute exact p-value with ties
##
## Two-sample Kolmogorov-Smirnov test
##
## data: df[df$GROUP == "AFRICA", "GNP"] and df[df$GROUP == "WEST_E_A", "GNP"]
## D = 1, p-value = 8.323e-10
## alternative hypothesis: two-sided