Answer:
Re = 15.29%
Explanation:
beta at current debt level:
11.5% = 5% + (beta x 6%)
6.5% = 6%beta
beta = 6.5% / 6 = 1.083
unlevered beta = 1.083 / {1 + [(1 - tax rate) x debt / equity]} = 1.083 / {1 + [(1 - 40%) x 25 / 75]} = 1.083 / 1.2 = 0.9025
cost of levered beta at 60% debt:
0.9025 = beta / {1 + [(1 - 40%) x 60 / 40]}
0.9025 x 1.9 = beta
beta = 1.7148
Re = 5% + (1.7148 x 6%) = 15.29%