Aresearch firm wants to compute an interval estimate with 90% confidence for the mean time to complete an employment test. assuming a population standard deviation of three hours, what is the required sample size if the error should be less than a half hour?

What would a student most likely use if he or she wanted to consult a secondary source

Psychologists studying infant memory want to determine at what age babies can remember specific events. an experimenter uses several puppets to demonstrate a series of actions while the infant watches. after a delay, the experimenter records how many of the actions the child imitates when playing with the puppets. what is the dependent variable?

Which political reform gave people the power to put a proposed law on the ballot? referendum initiative direct primary recall