Many adults owe money from their college loans for years into their professional careers. A newspaper would like to estimate the proportion of all adults in the city who have debts from college loans. To collect data, a random sample of 300 young adults between the ages of 25 and 35 is asked, "Do you have more than 5 dollars comma 000 in current college debts?” 68 percent of those sampled reported that they do have more than 5 dollars comma 000 in college-related debts. How might this sample be biased in obtaining an estimate of all adults in the city who have college debts?