Given that the hartford insurance company has hired you to poll a sample of adults about their car purchases.
Here the insurance company is using convenience sampling to select customers so they resorted to taking the names from telephone directories.
But this may not be reliable since persons owning cars need not have telephones and similarly persons having telephones need not own cars
Owning a car and name appearing in telephone directory need not be associated at all
So taking random sample of names from telephone directories may not give the required accurate result since here sample cannot be assumed to represent the population of car owners.