A4Q1

Load Data

library(readxl)
A4Q1 <- read_excel("C:/Users/CHEENA/Downloads/A4Q1.xlsx")
table(A4Q1$flavor)

## 
##  Chocolate      Mango Strawberry    Vanilla 
##         87         32         57         74

Observed Frequencies

observed <- table(A4Q1$flavor)
observed

## 
##  Chocolate      Mango Strawberry    Vanilla 
##         87         32         57         74

Bar Plot of Flavor Frequencies

barplot(observed,
        main = 'flavor',
        xlab = 'flavor',
        ylab = 'count',
        col = rainbow(length(unique(observed))))

Chi-Square Goodness-of-Fit Test

expected <- c(.20, .20, .20, .40)
chi_result <- chisq.test(x = observed, p = expected)
chi_result

## 
##  Chi-squared test for given probabilities
## 
## data:  observed
## X-squared = 41.6, df = 3, p-value = 4.878e-09

Effect Size (Cohen’s W)

w <- sqrt(as.numeric(chi_result$statistic) / sum(observed))
w

## [1] 0.4079216

Interpretation

A Chi-Square Goodness-of-Fit test was conducted to determine if there was a difference between the observed flavor frequencies and the expected frequencies. The results showed that there was a difference between the observed and expected frequencies, χ²(3) = 41.6, p < .001. The difference was moderate to large (Cohen’s W = .41).