Step 1. The ten months of Section 7.1 (Apple on SPY, total returns):
   By the deviation sums: intercept +1.42 percent, slope 1.476
   By lm: intercept +1.42 percent, slope 1.476, R-squared 0.736

Step 2. The market model, January 2021 to December 2025 (sixty months), excess on excess:
  Apple excess return on SPY excess return
    Intercept    estimate   +0.19 percent  SE 0.70  interval [  -1.21,   +1.58] percent
    spy_ex       estimate  +1.092  SE 0.158  interval [ +0.776,  +1.408]
    R-squared 0.452; residual standard deviation 5.28 points
    Durbin-Watson statistic 1.56

Step 3. The three-factor model of Table 7.1, same window:
  Apple excess return on the market, size, and value factors
    Intercept    estimate   +0.59 percent  SE 0.72  interval [  -0.85,   +2.03] percent
    mkt_rf       estimate  +1.001  SE 0.161  interval [ +0.678,  +1.324]
    smb          estimate  -0.024  SE 0.240  interval [ -0.506,  +0.457]
    hml          estimate  -0.353  SE 0.163  interval [ -0.680,  -0.025]
    R-squared 0.478; residual standard deviation 5.24 points

Part B, R lane solution: the factor model for Microsoft, same window and factors
  Microsoft excess return on the market, size, and value factors
    Intercept    estimate   +0.57 percent  SE 0.49  interval [  -0.41,   +1.54] percent
    mkt_rf       estimate  +1.022  SE 0.109  interval [ +0.803,  +1.241]
    smb          estimate  -0.528  SE 0.163  interval [ -0.854,  -0.201]
    hml          estimate  -0.587  SE 0.111  interval [ -0.809,  -0.366]
    R-squared 0.712; residual standard deviation 3.55 points
   Apple's value loading t statistic: -0.353 / 0.163 = -2.16

Chapter 7 lab complete.
