If you commit a crime, you need to make sure that you do not…

If you commit a crime, you need to make sure that you do not leave even the smallest speck of blood, hair, or other organic matter from your body. If you do, the DNA in this material can be amplified by ________, subjected to genetic analysis, and used to identify you as the perpetrator of the crime.

For each of the two scenarios below, please identify 1) what…

For each of the two scenarios below, please identify 1) what type of sample was collected (convenience, cluster, purposive, simple random, or stratified) and 2) note whether it was a probability or non-probability sample. 1.  A university researcher is interested in studying newly admitted community college transfer students. She begins by dividing the students into two subpopulations: US citizens, and international students. The researcher then randomly samples from each separate subpopulation to ensure that the final combined sample represents the same percentage of US citizens and international students seen in the general community college transfer population.   2.   A 4th grade teacher wants to explore  a newly implemented learning activity for helping classroom students better understand math concepts.  The teacher administers a pre- and post-test to students in her own class and to the class of a colleague that also teachers fourth grade at the school.