The speeds of two vehicles are 20 km/h and 45 km/h. Find the mean proportional between the two speeds.

The speeds of two vehicles are 20 km/h and 45 km/h. Find the mean proportional between the two speeds.
दो वाहनों की चाल क्रमशः 20 किमी/घंटा और 45 किमी/घंटा है। इन दोनों चालों के बीच माध्य समानुपाती (Mean Proportional) ज्ञात कीजिए।