Data Set 10-6: Drugs Used in Treating Schizophrenia All Block $$\begin{array} { c c } \text { Schizophrenics } & \text { Control Group } \\\hline 42 & 33 \\31 & 27 \\29 & 18\end{array}$$

Multiple Choice

Data Set 10-6: Drugs used in treating schizophrenia all block the reception of dopamine by neurons. (Dopamine is a neurotransmitter, which, when released by the axons of one nerve, inhibits the firing of the next nerve.) This fact led to the idea that schizophrenia occurs when too much dopamine is produced. Suppose the following data on dopamine production were obtained.
$$\begin{array} { c c } \text { Schizophrenics } & \text { Control Group } \\\hline 42 & 33 \\31 & 27 \\29 & 18\end{array}$$
-The study described in Data Set 10-6 is an example of

A) an independent-samples design
B) a paired-samples design
C) comparing a sample mean to a known population mean
D) unknown more information is required in order to decide, namely