Determine whether the sample is biased or unbiased. Explain. You want to estimate the number of books students in your school read over the summer. You survey every fourth student who enters the school. biased; Although the sample is representative of the population, the sample is not selected at random. biased; The sample is not selected at random and is not representative of the population because not all students read over the summer. unbiased; The sample is representative of the population, selected in a specific way, and small enough to provide accurate data. unbiased; The sample is representative of the population, selected at random, and large enough to provide accurate data.