The ratio of the mean proportional between 0.7 and 2.8 and the third proportional to 2.5 and 3.5 is:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 2 : 7
mean proportional between 0.7 and 2.8 = √(0.7 × 2.8) = 1.4
The third proportional to 2.5 and 3.5 = 3.5 × 3.5/2.5 = 0.49
Required ratio = 1.4 : 4.9 = 2 : 7