Load Dataset

Dataset6.4 <- read_excel("C:/Users/Student/Documents/Assignment6_AA/Dataset6.4.xlsx")
Before <- Dataset6.4$Stress_Pre
After  <- Dataset6.4$Stress_Post
Differences <- After - Before

Descriptive Statistics

cat("Before Stress Summary\n")
## Before Stress Summary
mean(Before, na.rm = TRUE)
## [1] 51.53601
median(Before, na.rm = TRUE)
## [1] 47.24008
sd(Before, na.rm = TRUE)
## [1] 17.21906
cat("After Stress Summary\n")
## After Stress Summary
mean(After, na.rm = TRUE)
## [1] 41.4913
median(After, na.rm = TRUE)
## [1] 40.84836
sd(After, na.rm = TRUE)
## [1] 18.88901

Histogram

hist(Before,
     main = "Histogram - Before Intervention",
     xlab = "Stress Score",
     col = "lightblue")

hist(After,
     main = "Histogram - After Intervention",
     xlab = "Stress Score",
     col = "lightgreen")

# Boxplot

boxplot(Before, After,
        names = c("Before", "After"),
        main = "Stress Score Distribution",
        col = c("lightblue", "lightgreen"))

Normality Test

Dataset6.4$Difference <- Dataset6.4$Stress_Post - Dataset6.4$Stress_Pre
shapiro.test(Dataset6.4$Difference)
## 
##  Shapiro-Wilk normality test
## 
## data:  Dataset6.4$Difference
## W = 0.87495, p-value = 0.0008963
ggqqplot(Dataset6.4$Difference)

Wilcoxon Signed-Rank Test

wilcox.test(Before, After, paired = TRUE)
## 
##  Wilcoxon signed rank exact test
## 
## data:  Before and After
## V = 620, p-value = 2.503e-09
## alternative hypothesis: true location shift is not equal to 0

Effect Size

wilcox_effsize(Dataset6.4,
               Stress_Post ~ Stress_Pre,
               paired = TRUE)
## # A tibble: 595 × 7
##    .y.         group1           group2           effsize    n1    n2 magnitude
##  * <chr>       <chr>            <chr>              <dbl> <int> <int> <ord>    
##  1 Stress_Post 30.5204972025781 30.6731265131384       1     1     1 large    
##  2 Stress_Post 30.5204972025781 30.7852339652292       1     1     1 large    
##  3 Stress_Post 30.5204972025781 31.4314800238469       1     1     1 large    
##  4 Stress_Post 30.5204972025781 33.0786101613194       1     1     1 large    
##  5 Stress_Post 30.5204972025781 35.7992685912432       1     1     1 large    
##  6 Stress_Post 30.5204972025781 35.8374122809619       1     1     1 large    
##  7 Stress_Post 30.5204972025781 37.1340472335316       1     1     1 large    
##  8 Stress_Post 30.5204972025781 37.4491497416786       1     1     1 large    
##  9 Stress_Post 30.5204972025781 37.8100239951164       1     1     1 large    
## 10 Stress_Post 30.5204972025781 39.2754776123911       1     1     1 large    
## # ℹ 585 more rows

Reporting Result

cat("The results showed a statistically significant difference between stress
levels before and after the intervention, V = 620, p < .001.")
## The results showed a statistically significant difference between stress
## levels before and after the intervention, V = 620, p < .001.