The sum of the fourth proportional of 4, 5, 16 and the mean proportional of 4, 16, is
Answer & explanation
Correct answer: option 2
The fourth proportional of 4, 5, 16 = \(\frac{16 × 5}{4}\) = 20
The mean proportion of 4, 16 = \(\sqrt {16 × 4}\) = 8
So, the sum of the fourth proportion and mean proportion = 20 + 8 = 28