please anwer A and B and show work

4 A larger and more modem main post office is to be constructed at a new bcation in Davis, Calcornia Growing suburbc caused a shift in the population density from where it was 40 The cooctinales and trips per dey to and from the seven mai source points and the current main post office, M, are shown in the following table M wil continue to act as a mail source point akes relocation. a Caciuate the canter of gravey os a bossible iscation tor tha naw ficety toundto the nearert weoly number/