Each month, the census bureau mails survey forms to 250,000 u. s. households asking questions about the people living in the household and about things such as motor vehicles and housing costs. telephone calls are made to households that don't return the form. in one month, responses were obtained from 240,000 of the households contacted. the population of interest is a. the 240,000 households contacted. b. the 250,000 households contacted. c. only u. s. households with phones. d. all u. s. households.