Cooghan asked his 19 classmates whether they were right or left-handed. there were 5 more right-handed classmates than left-handed classmates.

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.