report2.R

# 102430175

x <- c(78,49,11,44)
v = var(x)
print(v)

## [1] 753.6667

x10 <- x * 10
var_10 <- var(x10)
print(var_10)

## [1] 75366.67

ratio_var <- var_10 / v
print(ratio_var)

## [1] 100

x1000 <- c(78,49,11,44000)
mean_1000 = mean(x1000)
print(mean_1000)

## [1] 11034.5

median_1000 = median(x1000)
print(median_1000)

## [1] 63.5

mean_x = mean(x)
print(mean_x)

## [1] 45.5

median_x = median(x)
print(median_x)

## [1] 46.5

# 平均値は外れ値の影響を受けやすい
ratio_mean = mean_1000 / mean_x
print(ratio_mean)

## [1] 242.5165

# 中央値は外れ値の影響を受けづらい
ratio_median = median_1000 / median_x
print(ratio_median)

## [1] 1.365591

auto <- read.csv("C:/Users/mynam/.vscode/R/auto.csv")
auto_subset <- subset(auto, select = c(mpg, displacement, horsepower))
pairs(auto_subset)

# displacementとhorsepowerの相関係数を計算
cor_displacement_horsepower <- cor(auto$displacement, auto$horsepower)
cor_displacement_horsepower

## [1] 0.897257

# displacementとmpgの相関係数を計算
cor_displacement_mpg <- cor(auto$displacement, auto$mpg)
cor_displacement_mpg

## [1] -0.8051269