Answer:
There is 30% dissimilarity. 
Step-by-step explanation:
Dissimilarity index is = 0.5 × ∑ | (a÷A) - (b÷B) | 
 
Where ,
 a= population of white in neighborhood 
 b= population of black in neighborhood 
 A= total population of whites 
 B= total population of blacks 
 
Thus we can solve, 
 = 0.5 ×   
 = 0.3 
 Thus there is 30% dissimilarity.