Carry four significant digits throughout your calculations.
A mobile computer network consists of a number of computers (called nodes) that communicate with each other while moving throughout a region. A node that is out of transmission range of the other nodes, so that it is unable to communicate, is said to be partitioned. In studies carried in one state, a scientist found that in a network containing 185 nodes in which destinations were chosen at random from a uniform distribution, 19 nodes were partitioned. A second scientist found that in a network containing 165 nodes whose movements mimicked those on a college campus, 30 nodes were partitioned. Find a 99% confidence interval for the difference between the proportions of partitioned nodes in the two networks.