A family wants to rent a car to go on vacation. Company A charges ​$75.50 and 12¢ per mile. Company B charges ​$45.50 and 11¢ per mile. How much more does Company A charge for x miles than Company B​?

The coverage of a base station of a telecommunication company forms a disk with a radius of (kilometers). let be the distance of a cellphone from a base station. assume that the location of cellphones in use are randomly uniformly distributed within the disk. calculate the mean and variance for the random variable.