A cellphone service provider wants to analyze the signal strengths of its network. a) let X be the random variable that is the distance (in miles) that a customer will be to the nearest cellphone tower. Analyzing their database, the company finds that the probability density function is f(x) = 1/4 , 25 a < 6. Find the mean and the ariance of random variable X. b) The company is now interested in signal strengths. The company finds that the signal power/strength (in milliwatts) at a distance X from the tower is P(X) = 40/X2. What is the expected signal strength? %3D