You would set up a proportion for people that choose beach/ total
So (14+17+19)/(50+50+50) which simplifies to 50/150 or 1/3
From here we can set 1/3 = x/1200 and solve for x
To do this we would multiply each side by 1200 to isolate x
(1/3)×1200= 400
So x=400
Therefore, 400 people can be expected to pick the beach