# Chapter 1. Questions, Data, and Modeling Goals
# Reasoning Through Regression: Inference, Prediction, and Regularization with R
# Author: Prof. Dr. Bahadır Yüzbaşı
# Edition: 27 September 2026
# Run blocks in order in a fresh R session. See README.md.

# ===== Book block 1; source line 153 =====
y <- c(4, 8, 6, 10)
mean_y <- mean(y)
deviation <- y - mean_y
mean_y
deviation
sum(deviation)
sum(deviation^2)