RRStock = Rf + (RMarket − Rf) × BetaStock, where RR = required return, R = return, and Rf = risk-free rate
A bit of algebraic manipulation results in:
RMarket = [RRStock − Rf − (BetaStock × Rf)] / BetaStock = [8 − 5 − (-0.5 × 5)] / -0.5 = 0.5 / -0.5 = -1%
