Answer:
4600 people in the city might expect to have a swimming pool.
Explanation:
There is a total population of 10,000 people in Springfield.
Out of these 1000 people 250 people were interviewed. Of those, 115 had a swimming pool.
i.e. in 250 people the proportion of people those who have swimming pool is:

Hence among 10000 people the number of people who have swimming pool is: 0.46×10000=4600.
Hence out of 10000 people 4600 people have swimming pool.