The fourth proportional of 3, 7, and 15 is____.

The fourth proportional of 9, 8, and 18 is____.

The fourth proportional of 3, 4 and 6 is

(a) The fourth-proportional of 8, 10 and 12 is _________ . (b) The value of p when a/sqrt3 = b/sqrt5 = c/sqrt7 = (sqrt(3a) + sqrt(5b) - sqrt(7c))/p is ______ .

The fourth proportional to 4,7 and 20 is

What is the fourth proportional to 3,7 and 15 ?

Find the fourth proportional to 14, 28, and 21.

Find the fourth proportional of 3,12 and 4

If x is the fourth proportional to 36, 48 and 15, and 4.2, y, 9 and 13.5 are in proportion, then the difference between y and x is: