Beta系数计算

def solve(____):
    n = len(____)
    mean_stock = sum(____) / n
    mean_market = sum(____) / n
    cov = sum((____) * (____) for s, m in zip(____)) / (____)
    var_market = sum((____) ** ____ for m in market_returns) / (____)
    beta = cov / var_market
    return round(____)