Question:

A student wants to estimate the mean number of books that have been read by all students at his school over the summer. On Monday morning, he will survey the first 35 students who enter the library. Is this the best way to select a sample for this purpose?

(A) No. The student should survey students entering the library on more than one day of the week.
(B) No. The student should take a random sample of students entering the library instead.
(C) No. The student should take a random sample of students from all students, not just those entering the library.
(D) Yes. Selecting a sample in this way will not introduce the possibility of bias.

Level:

### Standards

7.SP.1: Understand that statistics can be used to gain information about a population by examining a sample of the population; generalizations about a population from a sample are valid only if the sample is representative of that population. Understand that random sampling tends to produce representative samples and support valid inferences.

S-IC.1: Understand statistics as a process for making inferences about population parameters based on a random sample from that population.