Installing the Required Packages install.packages(“readxl”) install.packages(“ggplot2”)

opening the Required Packages

library(readxl)
library(ggplot2)

loading DatasetA2

DatasetA2 <- read_excel("C:/Users/datta/Downloads/DatasetA2.xlsx")

creating a Contingency Table

table(DatasetA2$FavoriteDrink)
## 
## Coffee   Soda    Tea  Water 
##     26     29     28     17

Creating a Bar Chart

ggplot(DatasetA2, aes(x = FavoriteDrink, fill = FavoriteDrink)) +
  geom_bar() +
  labs(
    x = "Beverage Type",
    y = "Frequency",
    title = "Distribution of Beverage Preferences"
  ) +
  theme(
    text = element_text(size = 14),
    axis.title = element_text(size = 14),
    axis.text = element_text(size = 14),
    plot.title = element_text(size = 14),
    legend.position = "none"
  )

Conducting the Chi-Square Goodness-of-Fit Test

observed <- c(26, 29, 28,17) 
expected <- c(0.25, 0.25, 0.25,0.25)
chisq.test(x = observed, p = expected)
## 
##  Chi-squared test for given probabilities
## 
## data:  observed
## X-squared = 3.6, df = 3, p-value = 0.308

Interpret and Report the Results

A chi-square goodness-of-fit test indicated that the observed frequencies were different/ were not different from the expected frequencies, χ²(3) = 3.6, p = 0.308.

P value 0.3>0.05 so it is not statistically significant so there is no need to calculate Effect size