Instructions for CAPM Empirical Tests Using monthly returns from the January $2014$ to December $2023$ period for three selected stocks, a market index, and a government bill $($or RBI Repo rate$),$ we will conduct the following tests on the Sharpe$-$Lintner Capital Asset Pricing Model:

$1.10-$Year Sample Regression: Regress excess returns of each stock on the

market$$s excess returns, test the zero$-$intercept hypothesis, and report estimates and t$-$statistics. Conduct regression diagnostics.

$2.$ Subsample Tests: Repeat the tests on two equal subperiods, report estimates, t$-$statistics, and whether the CAPM is rejected in each subperiod.

$3.$ Portfolio Tests: Create an equal$-$weighted portfolio of the three stocks, perform the tests for the entire sample and subsamples, and report findings.

$4.$ Joint Hypothesis Test: Perform a joint test on the intercepts for all three stocks using the F$-$test for the entire sample and subsamples.

I have done part $1,2$ and $3.$ I need help with $4$ because I don't understand the MLRM being used since CAPM $($on individual stocks and the portfolio$)$ is essentially an SLRM$.$ Please mention the restricted and unrestricted model equations.