---
title: "Week 6 Starter Report"
format: html
---

## Question

How is car weight related to fuel efficiency in the `mtcars` dataset?

## Code

```{r}
library(ggplot2)

ggplot(mtcars, aes(x = wt, y = mpg)) +
  geom_point() +
  geom_smooth(method = "lm", se = FALSE) +
  labs(
    title = "Fuel efficiency decreases as car weight increases",
    x = "Weight (1000 lbs)",
    y = "Miles per gallon"
  )
```

## Summary

```{r}
model <- lm(mpg ~ wt, data = mtcars)
summary(model)
```

## Validation

The plot suggests a negative relationship between weight and miles per gallon. Before trusting this conclusion, inspect residuals and remember that this is an observational dataset.