# 1. What are the key factors influencing wine quality?  
library(ggplot2)
## Warning: package 'ggplot2' was built under R version 4.3.3
red_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityReds.csv")
white_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityWhites.csv")

ggplot(red_wine_data, aes(x = alcohol, y = quality)) +   
  geom_point() +   
  geom_smooth(method = "lm") +  
  labs(x = "Alcohol Content", y = "Quality") +  
  ggtitle("Red Wine: Alcohol Content vs. Wine Quality")
## `geom_smooth()` using formula = 'y ~ x'

ggplot(white_wine_data, aes(x = alcohol, y = quality)) +   
  geom_point() +  
  geom_smooth(method = "lm") +  
  labs(x = "Alcohol Content", y = "Quality") +
  ggtitle("White Wine: Alcohol Content vs. Wine Quality")  
## `geom_smooth()` using formula = 'y ~ x'

ggplot(red_wine_data, aes(x = quality)) +   
  geom_bar(fill = "blue") +  
  labs(x = "Quality", y = "Frequency") +
  ggtitle("Red Wine: Distribution of Wine Quality Ratings")  

ggplot(white_wine_data, aes(x = quality)) +   
  geom_bar(fill = "blue") +   
  labs(x = "Quality", y = "Frequency") +   
  ggtitle("White Wine: Distribution of Wine Quality Ratings")

# 2. What is the distribution of fixed acidity in red and white wines? 
library(ggplot2) 
library(gridExtra) 
## Warning: package 'gridExtra' was built under R version 4.3.3
red_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityReds.csv") 
white_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityWhites.csv") 
 
red_histogram <- ggplot(red_wine_data, aes(x = fixed.acidity)) + 
  geom_histogram(fill = "red", color = "black", bins = 20) + 
  labs(title = "Distribution of Fixed Acidity in Red Wines",    
       x = "Fixed Acidity",     
       y = "Frequency") 
 
white_histogram <- ggplot(white_wine_data, aes(x = fixed.acidity)) + 
  geom_histogram(fill = "blue", color = "black", bins = 20) + 
  labs(title = "Distribution of Fixed Acidity in White Wines",   
       x = "Fixed Acidity",    
       y = "Frequency") 
 
grid.arrange(red_histogram, white_histogram, nrow = 1) 

# 3. How does volatile acidity vary across different quality ratings of red wines? 
library(ggplot2) 
 
red_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityReds.csv")

ggplot(red_wine_data, aes(x = factor(quality), y = volatile.acidity)) +  
  geom_boxplot(fill = "blue") + 
  labs(title = "Volatile Acidity Across Di erent Quality Ratings of Red Wines",   
       x = "Quality Rating",      
       y = "Volatile Acidity") 

# 4. Is there a correlation between citric acid content and pH in white wines? 
library(ggplot2)
white_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityWhites.csv") 
 
ggplot(white_wine_data, aes(x = citric.acid, y = pH)) +
  geom_point() +   labs(title = "Citric Acid Content vs. pH in White Wines", 
                        x = "Citric Acid Content",     
                        y = "pH") + 
  geom_smooth(method = "lm", se = FALSE, color = "blue") 
## `geom_smooth()` using formula = 'y ~ x'

correlation <- cor(white_wine_data$citric.acid, white_wine_data$pH)
print(paste("Correlation coe icient:", correlation)) 
## [1] "Correlation coe icient: -0.163748211400624"
#5 What is the average residual sugar content in high-quality red wines?
library(dplyr)
## 
## Attaching package: 'dplyr'
## The following object is masked from 'package:gridExtra':
## 
##     combine
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
red_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityReds.csv")
high_quality_red_wines <- filter(red_wine_data, quality >= 7) 

average_residual_sugar <- mean(high_quality_red_wines$residual.sugar)
print(paste("Average residual sugar content in high-quality red wines:", round(average_residual_sugar, 2)))
## [1] "Average residual sugar content in high-quality red wines: 2.71"
# 6 How do chlorides levels di  er between red and white wines?
library(ggplot2)
red_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityReds.csv")
white_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityWhites.csv")

red_wine_data$type <- "Red Wine"

white_wine_data$type <- "White Wine"

combined_data <- rbind(red_wine_data, white_wine_data)
ggplot(combined_data, aes(x = type, y = chlorides, fill = type)) + 
  geom_boxplot() + 
  labs(title = "Chloride Levels in Red and White Wines",   
       x = NULL,     
       y = "Chloride Levels",   
       fill = "Wine Type") + 
  scale_fill_manual(values = c("red", "blue")) +  
  theme_minimal() 

# 7 Is there a relationship between free sulfur dioxide and total sulfur dioxide in white wines? 
library(ggplot2)

white_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityWhites.csv")

ggplot(white_wine_data, aes(x = free.sulfur.dioxide, y = total.sulfur.dioxide)) +
  geom_point() + 
  labs(title = "Relationship Between Free Sulfur Dioxide and Total Sulfur Dioxide in White Wines", 
       x = "Free Sulfur Dioxide",     
       y = "Total Sulfur Dioxide") +  
  geom_smooth(method = "lm", se = FALSE, color = "blue")
## `geom_smooth()` using formula = 'y ~ x'

correlation <- cor(white_wine_data$free.sulfur.dioxide, white_wine_data$total.sulfur.dioxide)

print(paste("Correlation coefficient:", correlation))
## [1] "Correlation coefficient: 0.615500965009836"
# 8 What is the range of density values observed in red wines?
red_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityReds.csv")
min_density <- min(red_wine_data$density) 
max_density <- max(red_wine_data$density)
print(paste("Range of density values observed in red wines:", min_density, "-", max_density))
## [1] "Range of density values observed in red wines: 0.99007 - 1.00369"
# 9 How does pH change with increasing alcohol content in red wines? 
library(ggplot2) 
red_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityReds.csv")
ggplot(red_wine_data, aes(x = alcohol, y = pH)) + 
  geom_point() +  
  labs(title = "pH vs. Alcohol Content in Red Wines",      
       x = "Alcohol Content",   
       y = "pH") +  
geom_smooth(method = "lm", se = FALSE, color = "blue") 
## `geom_smooth()` using formula = 'y ~ x'

# 10 Are sulphates levels higher in white wines compared to red wines?
library(ggplot2)
red_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityReds.csv")
white_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityWhites.csv") 
ggplot() +  
  geom_boxplot(data = red_wine_data, aes(x = "Red Wine", y = sulphates), fill = "red", alpha = 0.5) +  
  geom_boxplot(data = white_wine_data, aes(x = "White Wine", y = sulphates), fill = "blue", alpha = 0.5) +   labs(title = "Sulfates Levels in Red and White Wines",    
     x = NULL,    
     y = "Sulfates Levels") 

# 11 What is the median alcohol content in red wines of different quality ratings? 
library(dplyr)
red_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityReds.csv")
median_alcohol <- red_wine_data %>%
 group_by(quality) %>%
 summarize(median_alcohol = median(alcohol))
print(median_alcohol)
## # A tibble: 6 × 2
##   quality median_alcohol
##     <int>          <dbl>
## 1       3           9.93
## 2       4          10   
## 3       5           9.7 
## 4       6          10.5 
## 5       7          11.5 
## 6       8          12.2
# 12 How does fixed acidity aƯect the perceived quality of red wines?
library(ggplot2)
red_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityReds.csv")
ggplot(red_wine_data, aes(x = fixed.acidity, y = quality)) +
 geom_point() +
 labs(title = "Fixed Acidity vs. Quality Ratings in Red Wines",
 x = "Fixed Acidity",
 y = "Quality")

# 13 Can volatile acidity be used as a predictor of wine spoilage?
library(ggplot2)
wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityReds.csv")
ggplot(wine_data, aes(x = volatile.acidity, y = quality)) +
 geom_point() +
 labs(title = "Volatile Acidity vs. Quality Ratings in Red Wines",
 x = "Volatile Acidity",
 y = "Quality") +
 geom_smooth(method = "lm", se = FALSE, color = "blue") 
## `geom_smooth()` using formula = 'y ~ x'

# 14 What is the impact of citric acid on the acidity level of white wines?
library(ggplot2)
white_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityWhites.csv")
ggplot(white_wine_data, aes(x = citric.acid, y = pH)) +
 geom_point() +
 labs(title = "Citric Acid vs. pH Levels in White Wines",
 x = "Citric Acid",
 y = "pH")

# 15 Are there any trends between chlorides concentration and wine quality?
red_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityReds.csv")
ggplot(red_wine_data, aes(x = chlorides, y = quality)) +
 geom_point() +
 labs(title = "Chlorides vs. Quality Ratings in Red Wines",
 x = "Chlorides",
 y = "Quality")

ggplot(red_wine_data, aes(x = as.factor(quality), y = chlorides)) +
 geom_boxplot() +
 labs(title = "Distribution of Chlorides Concentration by Quality Ratings in Red Wines",
 x = "Quality",
 y = "Chlorides Concentration")

# 16 Is there a significant diƯerence in free sulfur dioxide levels between red and white wines?
library(tidyverse)
## Warning: package 'tidyverse' was built under R version 4.3.3
## ── Attaching core tidyverse packages ──────────────────────── tidyverse 2.0.0 ──
## ✔ forcats   1.0.0     ✔ stringr   1.5.1
## ✔ lubridate 1.9.3     ✔ tibble    3.2.1
## ✔ purrr     1.0.2     ✔ tidyr     1.3.1
## ✔ readr     2.1.5     
## ── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
## ✖ dplyr::combine() masks gridExtra::combine()
## ✖ dplyr::filter()  masks stats::filter()
## ✖ dplyr::lag()     masks stats::lag()
## ℹ Use the conflicted package (<http://conflicted.r-lib.org/>) to force all conflicts to become errors
red_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityReds.csv")
white_wine_data <- read.csv("C:/Users/risha/Downloads/wineQualityWhites.csv")
t_test_result <- t.test(red_wine_data$free.sulfur.dioxide, white_wine_data$free.sulfur.dioxide)
print(t_test_result)
## 
##  Welch Two Sample t-test
## 
## data:  red_wine_data$free.sulfur.dioxide and white_wine_data$free.sulfur.dioxide
## t = -54.428, df = 4461.9, p-value < 2.2e-16
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
##  -20.13315 -18.73318
## sample estimates:
## mean of x mean of y 
##  15.87492  35.30808