The forth proportional to 10,20,30 is?	Choices.
A) 20
B) 60
C) 45
D) 75
E) 100
Let the fourth proportional to 10,20,30 be x   then 10:20::30:x   10x = 20*30   x = 60   Answer is 60
<result>B</result>
The forth proportional to 10,20,30 is?