According to an article appearing in the newspaper's almanac, about 70% of all US households have a cell phone. In a city of 255,000, what is the probability that less than 100,000 have a cell phone?

I know about the x-u/o

so 100,000-178,000/

255,000 (.70)

p=.70

q=.30

o= 231.40

i dont know where to go next