You are standing in line at the super market when a scientist standing behind you strikes up a conversation with you. He tells you that he is running an experiment to try to increase the intelligence of monkeys. He has 20 chimpanzees. He assingned half of them to the treatment group and the other half is living under the same conditions without the treatment as a control. He assigned them to the groups by age, putting all of the older ones in the control group and the younger ones in the treatment group. He is using a two sample z-test to try to prove his theories. (using scores form an intelligence test). As a responsible statician (someone who practices statistics) you feel a need to tell him what he is doing wrong. Explain three things that he is doing wrong ( or that break some statistcal requirement).