We know from Capital asset pricing model that expected return (ER) of any stock can be calculated as
ER = Rf + beta* ( Rm - Rf)
where, Rf is risk free rate
Rm is expected return on market. Therefore,
0.128 = Rf + 1.19* (0.118 - Rf)
which is equivalent to
0.19 Rf = 0.140 - 0.128
Or, risk free rate, Rf = 0.0654 ~ 6.54%