Practice Assignment- Creating Barplots with Error Bars

# Load required libraries
library(ggplot2)
library(dplyr)

## 
## Attaching package: 'dplyr'

## The following objects are masked from 'package:stats':
## 
##     filter, lag

## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union

# Summarize data to calculate mean and standard error
data_summary <- mtcars %>%
  group_by(cyl) %>%
  summarise(
    mean_mpg = mean(mpg),
    se_mpg = sd(mpg) / sqrt(n())
  )

# Create a bar plot with error bars
ggplot(data_summary, aes(x = factor(cyl), y = mean_mpg)) +
  geom_bar(stat = "identity", fill = "skyblue", color = "black", width = 0.6) +  # Bar plot
  geom_errorbar(aes(ymin = mean_mpg - se_mpg, ymax = mean_mpg + se_mpg), 
                width = 0.2, color = "red") +  # Error bars
  labs(title = "Bar Plot of Mean MPG by Cylinders",
       x = "Number of Cylinders",
       y = "Mean MPG") +
  theme_minimal()  # Aesthetic improvements