The hourly median power (in decibels) of received radio signals transmitted between two cities follows a lognormal distribution with parameter values u = 3.5 and o2 = 1.22.

(5 points) What is the 90th percentile of this distribution?

(5 points) What is the probability that received power for one of these radio signals is
less than 150 decibels?

(5 point) Consider a random sample of 10 radio signals. What is the probability that for
6 of these signals, the received power is less than 150 decibels?