Answer:
The dollar amount of the investment in Stock D is (x=$156470.59)
Explanation:
Let assume investment in Stock D = $x
Hence investment in Stock E = (210,000-x)
Portfolio beta=Respective betas * Respective investment weights
1= (x/210,000*0.87) + (210,000-x) /210,000*1.38[Beta of market=1]
(1*210,000) = 0.87x + 289800 -1.38x
290,000=0.87x+289800-1.38x
Hence x=(289800-210,000)/(1.38-0.87)
x= 79,800 / 0.51
x=156470.5882
x=$156470.59