The fourth proportional to 5, 8, 15 is:	Pick:
A) 15 B) 5 C) 24 D) 8 E) 28
Let the fourth proportional to 5, 8, 15 be x.   Then, 5 : 8 : 15 : x   = 5x = (8 x 15)   x = (8 x 15)/5= 24.   Answer is 24.
<result>C</result>
The fourth proportional to 5, 8, 15 is: