Find the mean proportional between 25 and 81.
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 45.
Let c be the mean proportional between a and b, the
c2 = ab
Let the mean proportional between 25 and 81 be x.
According to the given question,
x2 = 25 × 81
⇒ x = 5 × 9
⇒ x = 45