---
title: "Activity_Week_8"
output: pdf_document
---

```{r}
library(gapminder)
library(dplyr)
library(ggplot2)

# Subset data for 2002
data_2002 <- gapminder %>% filter(year == 2002, continent %in% c("Europe", "Asia"))

# Check sample size
table(data_2002$continent)

# Check normality (Shapiro-Wilk) - sample size is large, so approximation OK
by(data_2002$lifeExp, data_2002$continent, shapiro.test)


# Check homogeneity of variances
var.test(lifeExp ~ continent, data = data_2002)

```

```{r}

# Boxplot for visual inspection
ggplot(data_2002, aes(x = continent, y = lifeExp)) +
  geom_boxplot() +
  theme_minimal()


# Run t-test
t.test(lifeExp ~ continent, data = data_2002, var.equal = TRUE)
```