In a normal curve, the percentage of the scores lower than two standard deviations below the mean is approximately __________

Drugs that increase the activity of a particular neurotransmitter are said to be __________ of that neurotransmitter

Fill in the blank with the appropriate word.

It is possible that the effect sizes were larger for influenza vaccination than for other forms of vaccination because ______.

A. the non-flu studies included a wide range of vaccines B. flu vaccination is more familiar and contributed to a clearer perceived risk C. the non-flu vaccine requires multiple vaccinations that may attenuate the risk perception D. all of these