If a t test for independent means is conducted, how many degrees of freedom will be used to locate the cutoff score in the t table?

Since we normally cannot have access to the full population of interest, researchers are faced with taking a representative sample of the population. Which of the following is NOT true of a representative sample?

a. One can only generalize from the sample to the population it adequately represents. b. The representative sample has to closely match the overall characteristics of the population of interest. c. A representative sample must include members of different racial groups, even when the target population is of one race. d. A representative sample is a way by which one can generalize to the population of interest without having access to the full population.

A person with Parkinson's disease is MOST likely to have a problem with which of the following neurotransmitters?

a. acetylcholine c. serotonin b. dopamine d. norepinephrine