#introduction

data set over view

# mean of  mtcars data set 
mean(mtcars$mpg)
## [1] 20.09062
# median of  mtcars data set 

median(mtcars$hp)
## [1] 123
# sum of  mtcars data set 

sum(mtcars$cyl == 8)
## [1] 14
# range  of  mtcars data set 

range(mtcars$wt)
## [1] 1.513 5.424
sd(mtcars$mpg)
## [1] 6.026948

Visual Analysis Questions

plot(mtcars$hp, mtcars$mpg, main="Horsepower vs MPG", 
     xlab="Horsepower", ylab="Miles per Gallon", col="blue", pch=19)

box plot of mpg grouped by the number of cylinders

boxplot(mpg ~ cyl, data=mtcars, main="MPG by Cylinder Count", 
        xlab="Cylinders", ylab="Miles per Gallon", col=c("orange","green","purple"))

histogram of car weights

hist(mtcars$wt, main="Distribution of Car Weights", 
     xlab="Weight (1000 lbs)", col="lightblue", breaks=10)

bar plot showing the count of cars by gear type.

{r} barplot(table(mtcars$gear), main=“Number of Cars by Gear Type”, xlab=“Gears”, ylab=“Count”, col=c(“red”,“green”,“blue”))

Pie charts

## bar plot showing the count of cars by gear type.

barplot(table(mtcars$gear), main="Number of Cars by Gear Type",
        xlab="Gears", ylab="Count", col=c("red","green","blue"))

# install.packages("ggplot2")
library(ggplot2)

df <- as.data.frame(table(mtcars$cyl))
colnames(df) <- c("Cylinders", "Count")

ggplot(df, aes(x = "", y = Count, fill = factor(Cylinders))) +
  geom_bar(stat = "identity", width = 1) +
  coord_polar("y", start = 0) +
  labs(title = "Pie Chart: Cars by Cylinder Count",
       fill = "Cylinders") +
  theme_void()

## line charts

# install.packages("ggplot2")  # if needed
library(ggplot2)
df <- mtcars
df$model <- rownames(df)
df$model <- factor(df$model, levels = df$model)  # preserve original order

ggplot(df, aes(x = model, y = mpg, group = 1)) +
  geom_line() +
  geom_point() +
  labs(title = "MPG by car (mtcars)", x = "Car model", y = "MPG") +
  theme_minimal() +
  theme(axis.text.x = element_text(angle = 45, hjust = 1))