Answer:
Cost of equity from retained earning is 11.84 %
Step-by-step explanation:
We have given dividend 

Price at the beginning 

Growth rate g = 8 %
We have to find the cost of equity from retained earning 
Now dividend at the end of year 
 = $0.80×1.08 = 0.864
 = $0.80×1.08 = 0.864
We know that cost of equity is given by
 
 
So cost of equity from retained earning is 11.84 %