At Westonci.ca, we make it easy to get the answers you need from a community of informed and experienced contributors. Get detailed and precise answers to your questions from a dedicated community of experts on our Q&A platform. Explore comprehensive solutions to your questions from a wide range of professionals on our user-friendly platform.

Circle O has diameter AB. Extended AB through B at some point P, and draw its tangent to O with intersection point D. Given that PB = 3 and PD = 4, compute the radius of O. Express your answer as a common fraction in reduced form.